Special Report on Diseases of the Horse
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Title: Special Report on Diseases of the Horse
Author: United States. Bureau of Animal Industry
W. H. Harbaugh
Rush Shippen Huidekoper
Charles B. Michener
Leonard Pearson
Release date: November 7, 2007 [eBook #23403]
Language: English
Other information and formats: www.gutenberg.org/ebooks/23403
Credits: Produced by Audrey Longhurst, Kevin Handy, Josephine
Paolucci and the Online Distributed Proofreading Team at
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*** START OF THE PROJECT GUTENBERG EBOOK SPECIAL REPORT ON DISEASES OF THE HORSE ***
Produced by Audrey Longhurst, Kevin Handy, Josephine
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U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY.
A. D. MELVIN, CHIEF OF BUREAU.
* * * * *
SPECIAL REPORT
ON
DISEASES OF THE HORSE.
BY
Drs. PEARSON, MICHENER, LAW, HARBAUGH, TRUMBOWER, LIAUTARD, HOLCOMBE,
HUIDEKOPER, MOHLER, EICHHORN, HALL, AND ADAMS.
* * * * *
REVISED EDITION, 1916.
[Illustration]
WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1916.
DEPARTMENT OF AGRICULTURE,
_Washington, March 30, 1916._
* * * * *
Transcriber's note: The italic markup for single italized letters are
deleted for easier reading. Minor typos have been corrected and footnotes
moved to the end of the sections.
* * * * *
This edition of the Special Report on Diseases of the Horse has been
prepared in compliance with House Concurrent Resolution No. 13, passed
February 3, 1916, as follows:
_Resolved by the House of Representatives (the Senate
concurring)_, That there be printed and bound in cloth one
hundred thousand copies of the Special Report on the Diseases
of the Horse, the same to be first revised and brought to date,
under the supervision of the Secretary of Agriculture; seventy
thousand copies for the use of the House of Representatives and
thirty thousand for use of the Senate.
Since the original edition issued by the Department in 1890 several
editions have been printed by order of Congress. The work was reprinted
in 1896, and revised and reprinted in 1903, 1908, and 1911. In
accordance with the foregoing resolution it again has been revised so as
to embody the latest practical development of knowledge of the subject.
D. F. HOUSTON,
_Secretary._
CONTENTS.
Page.
The examination of a sick horse. By Leonard Pearson 7
Fundamental principles of disease. By Rush Shippen Huidekoper 27
Methods of administering medicines. By Ch. B. Michener 44
Diseases of the digestive organs. By Ch. B. Michener 49
Diseases of the respiratory organs. By W. H. Harbaugh 95
Diseases of the urinary organs. By James Law 134
Diseases of the generative organs. By James Law 164
Diseases of the nervous system. By M. R. Trumbower 210
Diseases of the heart, blood vessels, and lymphatics.
By M. R. Trumbower 247
Diseases of the eye. By James Law 274
Lameness. By A. Liautard 298
Diseases of the fetlock, ankle, and foot. By A. A. Holcombe 395
Diseases of the skin. By James Law 458
Wounds and their treatment. By Ch. B. Michener 484
Infectious diseases. By Rush Shippen Huidekoper 507
Shoeing. By John W. Adams 583
Index 607
ILLUSTRATIONS.
PLATES.
Page.
PLATE
I. Inflammation 32
II. Inflammation 32
III. Digestive apparatus 48
IV. Age of horses as indicated by teeth 58
V. Intestinal worms 92
VI. Bots 92
VII. Position of the left lung 112
VIII. Longitudinal section through kidney 136
IX. Microscopic anatomy of kidney 136
X. Microscopic anatomy of kidney 136
XI. Calculi and instrument for removal 152
XII. Normal presentation 192
XIII. Some factors in difficult labor 192
XIV. Instruments used in difficult labor 192
XV. Abnormal presentations 200
XVI. Abnormal presentations 200
XVII. Abnormal presentations 200
XVIII. Abnormal presentations 200
XIX. The nervous system 216
XX. Interior of chest, showing position of heart and diaphragm 248
XXI. Circulatory apparatus 248
XXII. Diagrammatic vertical section through horse's eye 277
XXIII. Skeleton of horse 304
XXIV. Superficial layer of muscles 304
XXV. Splint 312
XXVI. Ringbone 312
XXVII. Various types of spavin 312
XXVIII. Bone spavin 312
XXIX. Bone spavin 312
XXX. Dislocation of shoulder and elbow, Bourgelat's apparatus 360
XXXI. The sling in use 360
XXXII. Anatomy of foot 400
XXXIII. Anatomy of foot 400
XXXIV. Anatomy and diseases of foot 400
XXXV. Sound and contracted feet 400
XXXVI. Quarter crack and remedies 432
XXXVII. Foundered feet 432
XXXVIII. The skin and its diseases 458
XXXIX. Mites that infest the horse 480
XL. Glanders 544
XLI. Glanders 544
XLII. Glanders 544
TEXT FIGURES.
Page.
FIG.
1. Ground surface of a right fore hoof of the
"regular" form 590
2. Pair of fore feet of regular form in regular standing position 591
3. Pair of fore feet of base-wide form in toe-wide standing
position 591
4. Pair of fore feet of base-narrow form in toe-narrow standing
position 592
5. Side view of an acute-angled fore foot, of a regular fore
foot, and of a stumpy fore foot 592
6. Side view of foot with the foot-axis broken backward as a
result of too long a toe 595
7. Left fore hoof of a regular form, shod with a plain fullered
shoe 599
8. Side view of hoof and fullered shoe 599
9. An acute-angled left fore hoof shod with a bar shoe 601
10. A fairly formed right fore ice shoe for a roadster 601
11. Left fore hoof of regular form shod with a rubber pad and
"three-quarter" shoe 602
12. A narrow right fore hoof of the base-wide standing position
shod with a plain "dropped crease" shoe 602
13. Hoof surface of a right hind shoe to prevent interfering 603
14. Ground surface of shoe shown in fig. 13 603
15. Side view of a fore hoof shod so as to quicken the "breaking
over" in a "forger" 604
16. Side view of a short-toed hind hoof of a forger 604
17. A toe-weight shoe to increase the length of stride of fore
feet 605
18. Most common form of punched heel-weight shoe to induce high
action in fore feet 605
SPECIAL REPORT ON DISEASES OF THE HORSE.
THE EXAMINATION OF A SICK HORSE.
By Leonard Pearson, B. S., V. M. D.
In the examination of a sick horse it is important to have a method or
system. If a definite plan of examination is followed one may feel
reasonably sure, when the examination is finished, that no important
point has been overlooked and that the examiner is in a position to
arrive at an opinion that is as accurate as is possible for him. Of
course, an experienced eye can see, and a trained hand can feel, slight
alterations or variations from the normal that are not perceptible to
the unskilled observer. A thorough knowledge of the conditions that
exist in health is of the highest importance, because it is only by a
knowledge of what is right that one can surely detect a wrong condition.
A knowledge of anatomy, or of the structure of the body, and of
physiology, or the functions and activities of the body, lie at the
bottom of accuracy of diagnosis. It is important to remember that
animals of different races or families deport themselves differently
under the influence of the same disease or pathological process. The
sensitive and highly organized thoroughbred resists cerebral depression
more than does the lymphatic draft horse. Hence a degree of fever that
does not produce marked dullness in a thoroughbred may cause the most
abject dejection in a coarsely bred, heavy draft horse. This and similar
facts are of vast importance in the diagnosis of disease and in the
recognition of its significance.
The order of examination, as given hereafter, is one that has proved to
be comparatively easy of application and sufficiently thorough for the
purpose of the readers of this work, and is recommended by several
writers.
HISTORY.
It is important to know, first of all, something of the origin and
development of the disease; therefore the cause should be looked for.
The cause of a disease is important, not only in connection with
diagnosis, but also in connection with treatment. The character of feed
that the horse has had, the use to which he has been put, and the kind
of care he has received should all be closely inquired into. It may be
found by this investigation that the horse has been fed on damaged feed,
such as brewers' grains or moldy silage, and this may be sufficient to
explain the profound depression and weakness that are characteristic of
forage poisoning. If it is learned that the horse has been kept in the
stable without exercise for several days and upon full rations, and that
he became suddenly lame in his back and hind legs, and finally fell to
the ground from what appeared to be partial paralysis, this knowledge,
taken in connection with a few evident symptoms, will be enough to
establish a diagnosis of azoturia (excess of nitrogen in the urine). If
it is learned that the horse has been recently shipped in the cars or
has been through a dealer's stable, we have knowledge of significance in
connection with the causation of a possible febrile disease, which is,
under these conditions, likely to prove to be influenza, or edematous
pneumonia.
It is also important to know whether the particular horse under
examination is the only one in the stable, or on the premises, that is
similarly afflicted. If it is found that several horses are afflicted
much in the same way, we have evidence of a common cause of disease
which may prove to be of an infectious nature.
Another item of importance in connection with the history of the case
relates to the treatment that the horse may have had before he is
examined. It sometimes happens that medicine given in excessive
quantities produces symptoms resembling those of disease, so it is
important that the examiner be fully informed as to the medication that
has been employed.
ATTITUDE AND GENERAL CONDITION.
Before beginning the special examination, attention should be paid to
the attitude and general condition of the animal. Sometimes horses
assume positions that are characteristic of a certain disease. For
example, in tetanus (lockjaw) the muscles of the face, neck, and
shoulders are stiff and rigid, as well as the muscles of the jaw. This
condition produces a peculiar attitude, that once seen is subsequently
recognized as rather characteristic of the disease. A horse with tetanus
stands with his muscles tense and his legs in a somewhat bracing
position, as though he were gathered to repel a shock. The neck is stiff
and hard, the head is slightly extended upon it, and the face is drawn,
and the nostrils are dilated. The tail is usually held up a little, and
when pressed down against the thighs it springs back to its previous
position. In inflammation of the throat, as in pharyngolaryngitis, the
head is extended upon the neck and the angle between the jaw and the
lower border of the neck is opened as far as possible to relieve the
pressure that otherwise would fall upon the throat. In dumminess, or
immobility, the hanging position of the head and the stupid expression
are rather characteristic. In pleurisy, peritonitis, and some other
painful diseases of the internal organs, the rigid position of the body
denotes an effort of the animal to avoid pressure upon and to protect
the inflamed sensitive region.
The horse may be down in the stall and unable to rise. This condition
may result from paraplegia (paralysis), from azoturia, from forage
poisoning, from tetanus, or from painful conditions of the bones or
feet, such as osteoporosis or founder. Lying down at unusual times or in
unusual positions may indicate disease. The first symptom of colic may
be a desire on the part of the horse to lie down at an unusual or
inappropriate time or place. Sometimes disinclination to lie down is an
indication of disease. When there is difficulty in breathing, the horse
knows that he can manage himself better upon his feet than upon his
breast or his side. It happens, therefore, that in nearly all serious
diseases of the respiratory tract he stands persistently, day and night,
until recovery has commenced and breathing is easier, or until the
animal falls from sheer exhaustion. If there is stiffness and soreness
of the muscles, as in rheumatism, inflammation of the muscles from
overwork, or of the bones in osteoporosis, or of the feet in founder, or
if the muscles are stiff and beyond control of the animal, as in
tetanus, a standing position is maintained, because the horse seems to
realize that when he lies down he will be unable to rise.
Abnormal attitudes are assumed in painful diseases of the digestive
organs (colic). A horse with colic may sit upon his haunches, like a
dog, or may stand upon his hind feet and rest upon his knees in front,
or he may endeavor to balance himself upon his back, with all four feet
in the air. These positions are assumed because they give relief from
pain by lessening pressure or tension upon the sensitive structures.
Under the general condition of the animal it is necessary to observe the
condition or state of nutrition, the conformation, so far as it may
indicate the constitution, and the temperament. By observing the
condition of nutrition one may be able to determine to a certain extent
the effect that the disease has already had upon the animal and to
estimate the amount of strength that remains and that will be available
for the repair of the diseased tissues. A good condition of nutrition is
shown by the rotundity of the body, the pliability and softness of the
skin, and the tone of the hair. If the subcutaneous fat has disappeared
and the muscles are wasted, allowing the bony prominences to stand out;
if the skin is tight and inelastic and the coat dry and harsh, we have
evidence of a low state of nutrition. This may have resulted from a
severe and long-continued disease or from lack of proper feed and care.
When an animal is emaciated--that is, becomes thin--there is first a
loss of fat and later the muscles shrink. By observing the amount of
shrinkage in the muscles one has some indication as to the duration of
the unfavorable conditions under which the animal has lived.
By constitution we understand the innate ability of the animal to
withstand disease or unfavorable conditions of life. The constitution
depends largely upon the conformation. The type of construction that
usually accompanies the best constitution is deep, broad chest, allowing
plenty of room for the lungs and heart, indicating that these vital
organs are well developed; capacious abdomen, allowing sufficient space
for well-developed organs of digestion; the loins should be short--that
is, the space should be short between the last rib and the point of the
hip; the head and neck should be well molded, without superfluous or
useless tissue; this gives a clear-cut throat. The ears, eyes, and face
should have an expression of alertness and good breeding. The muscular
development should be good; the shoulders, forearms, croup, and thighs
must have the appearance of strength. The withers are sharp, which means
that they are not loaded with useless, superfluous tissue; the legs are
straight and their axes are parallel; the knees and hocks are low, which
means that the forearms and thighs are long and the cannons relatively
short. The cannons are broad from in front to behind and relatively thin
from side to side. This means that the bony and tendinous structures of
the legs are well developed and well placed. The hoofs are compact,
tense, firm structures, and their soles are concave and frogs large.
Such a horse is likely to have a good constitution and to be able to
resist hard work, fatigue, and disease to a maximum degree. On the other
hand, a poor constitution is indicated by a shallow, narrow chest, small
bones, long loins, coarse neck and head, with thick throat, small, bony,
and muscular development, short thighs and forearms, small joints, long,
round cannons, and hoofs of open texture with flat soles.
The temperament is indicated by the manner in which the horse responds
to external stimuli. When the horse is spoken to, or when he sees or
feels anything that stimulates or gives alarm, if he responds actively,
quickly, and intelligently, he is said to be of lively, or nervous,
temperament. On the other hand, if he responds in a slow, sluggish
manner, he is said to have a sluggish, or lymphatic, temperament. The
temperament is indicated by the gait, by the expression of the face, and
by the carriage of the head and ears. The nature of the temperament
should be taken into consideration in an endeavor to ascertain the
severity of a given case of illness, because the general expression of
an animal in disease as well as in health depends to a large extent on
the temperament.
THE SKIN AND THE VISIBLE MUCOUS MEMBRANES.
The condition of the skin is a fair index to the condition of the
animal. The effect of disease and emaciation upon the pliability of the
skin have been referred to above. There is no part of the body that
loses its elasticity and tone as a result of disease sooner than the
skin. The practical herdsman or flockmaster can gain a great deal of
information as to the condition, of an animal merely by grasping the
coat and looking at and feeling the skin. Similarly, the condition of
the animal is shown to a certain extent by the appearance of the mucous
membranes. For example, when the horse is anemic as a result of disease
or of inappropriate feed the mucous membranes become pale. This change
in the mucous membranes can be seen most readily in the lining of the
eyelids and in the lining of the nostril. For convenience of examination
the eyelids can readily be everted. Paleness means weak circulation or
poor blood. Increased redness occurs physiologically in painful
conditions, excitement, and following severe exertion. Under such
conditions the increase of circulation is transitory. In fevers there is
an increased redness in the mucous membrane, and this continues so long
as the fever lasts. In some diseases red spots or streaks form in the
mucous membrane. This usually indicates an infectious disease of
considerable severity, and occurs in blood poisoning, purpura
hemorrhagica, hemorrhagic septicemia, and in urticaria. When the liver
is deranged and does not operate, or when the red-blood corpuscles are
broken down, as in serious cases of influenza, there is a yellowish
discoloration of the mucous membrane. The mucous membranes become bluish
or blue when the blood is imperfectly oxidized and contains an excess of
carbon dioxid. This condition exists in any serious disease of the
respiratory tract, as pneumonia, and in heart failure.
The temperature of the skin varies with the temperature of the body. If
there is fever the temperature of the skin is likely to be increased.
Sometimes, however, as a result of poor circulation and irregular
distribution of the blood, the body may be warmer than normal, while the
extremities (the legs and ears) may be cold. Where the general surface
of the body becomes cold it is evident that the small blood vessels in
the skin have contracted and are keeping the blood away, as during a
chill, or that the heart is weak and is unable to pump the blood to the
surface, and that the animal is on the verge of collapse.
The skin is moist, to a certain degree, at all times in a healthy horse.
This moisture is not in the form of a perceptible sweat, but it is
enough to keep the skin pliable and to cause the hair to have a soft,
healthy feel. In some chronic diseased conditions and in fever, the skin
becomes dry. In this case the hair has a harsh feel that is quite
different from the condition observed in health, and from the fact of
its being so dry the individual hairs do not adhere to one another, they
stand apart, and the animal has what is known as "a staring coat." When,
during a fever, sweating occurs, it is usually an indication that the
crisis is passed. Sometimes sweating is an indication of pain. A horse
with tetanus or azoturia sweats profusely. Horses sweat freely when
there is a serious impediment to respiration; they sweat under
excitement, and, of course, from the well-known physiological causes of
heat and work. Local sweating, or sweating of a restricted area of the
body, denotes some kind of nerve interference.
Swellings of the skin usually come from wounds or other external causes
and have no special connection with the diagnosis of internal diseases.
There are, however, a number of conditions in which the swelling of the
skin is a symptom of a derangement of some other part of the body. For
example, there is the well-known "stocking," or swelling of the legs
about the fetlock joints, in influenza. There is the soft swelling of
the hind legs that occurs so often in draft horses when standing still
and that comes from previous inflammation (lymphangitis) or from
insufficient heart power. Dropsy, or edema of the skin, may occur
beneath the chest or abdomen from heart insufficiency or from chronic
collection of fluid in the chest or abdomen (hydrothorax, ascites, or
anemia). In anasarca or purpura hemorrhagica large soft swellings appear
on any part of the skin, but usually on the legs, side of the body, and
about the head.
Gas collects under the skin in some instances. This comes from a local
inoculation with an organism which produces a fermentation beneath the
skin and causes the liberation of gas which inflates the skin, or the
gas may be air that enters through a wound penetrating some
air-containing organ, as the lungs. The condition here described is
known as emphysema. Emphysema may follow the fracture of a rib when the
end of a bone is forced inward and caused to penetrate the lung, or it
may occur when, as a result of an ulcerating process, an organ
containing air is perforated. This accident is more common in cattle
than it is in horses. Emphysema is recognized by the fact that the
swelling that it causes is not hot or sensitive on pressure. It emits a
peculiar crackling sound when it is stroked or pressed upon.
Wounds of the skin may be of importance in the diagnosis of internal
disease. Wounds over the bony prominence, as the point of the hip, the
point of the shoulder, and the greatest convexity of the ribs, occur
when a horse is unable to stand for a long time and, through continually
lying upon his side, has shut off the circulation to the portion of the
skin that covers parts of the body that carry the greatest weight, and
in this way has caused them to mortify. Little, round, soft, doughlike
swellings occur on the skin and may be scattered freely over the surface
of the body when the horse is afflicted with urticaria. Similar
eruptions, but distributed less generally, about the size of a silver
dollar, may occur as a symptom of dourine, or colt distemper. Hard
lumps, from which radiate welt-like swellings of the lymphatics, occur
in glanders, and blisterlike eruptions occur around the mouth and
pasterns in horsepox.
THE ORGANS OF CIRCULATION.
The first item in this portion of the examination consists in taking the
pulse. The pulse may be counted and its character may be determined at
any point where a large artery occupies a situation close to the skin
and above a hard tissue, such as a bone, cartilage, or tendon. The most
convenient place for taking the pulse of the horse is at the jaw. The
external maxillary artery runs from between the jaws, around the lower
border of the jawbone, and up on the outside of the jawbone to the face.
It is located immediately in front of the heavy muscles of the cheek.
Its throb can be felt most distinctly just before it turns around the
lower border of the jawbone. The balls of the first and second or of the
second and third fingers should be pressed lightly on the skin over this
artery when its pulsations are to be studied.
The normal pulse of the healthy horse varies in frequency as follows:
Stallion 28 to 32 beats per minute.
Gelding 33 to 38 beats per minute.
Mare 34 to 40 beats per minute.
Foal 2 to 3 years old 40 to 50 beats per minute.
Foal 6 to 12 months old 45 to 60 beats per minute.
Foal 2 to 4 weeks old 70 to 90 beats per minute.
The pulse is accelerated by the digestion of rich food, by hot weather,
exercise, excitement, and alarm. It is slightly more rapid in the
evening than it is in the morning. Well-bred horses have a slightly more
rapid pulse than sluggish, cold-blooded horses. The pulse should be
regular; that is, the separate beats should follow each other after
intervals of equal length, and the beats should be of equal fullness, or
volume.
In disease, the pulse may become slower or more rapid than in health.
Slowing of the pulse may be caused by old age, great exhaustion, or
excessive cold. It may be due to depression of the central nervous
system, as in dumminess, or be the result of the administration of
drugs, such as digitalis or strophantus. A rapid pulse is almost always
found in fever, and the more severe the infection and the weaker the
heart the more rapid is the pulse. Under these conditions, the beats may
rise to 80, 90, or even 120 per minute. When the pulse is above 100 per
minute the outlook for recovery is not promising, and especially if this
symptom accompanies high temperature or occurs late in an infectious
disease. In nearly all of the diseases of the heart and in anemia the
pulse becomes rapid.
The pulse is irregular in diseases of the heart, and especially where
the valves are affected. The irregularity may consist in varying
intervals between the beats or the dropping of one or more beats at
regular or irregular intervals. The latter condition sometimes occurs in
chronic diseases of the brain. The pulse is said to be weak, or soft,
when the beats are indistinct, because little blood is forced through
the artery by each contraction of the heart. This condition occurs when
there is a constriction of the vessels leading from the heart and it
occurs in certain infectious and febrile diseases, and is an indication
of heart weakness.
In examining the heart itself it is necessary to recall that it lies in
the anterior portion of the chest slightly to the left of the median
line and that it extends from the third to the sixth rib. It extends
almost to the breastbone, and a little more than half of the distance
between the breastbone and the backbone. In contracting, it rotates
slightly on its axis, so that the point of the heart, which lies below,
is pressed against the left chest wall at a place immediately above the
point of the elbow. The heart has in it four chambers--two in the left
and two in the right side. The upper chamber of the left side (left
auricle) receives the blood as it comes from the lungs, passes it to the
lower chamber of the left side (left ventricle), and from here it is
sent with great force (for this chamber has very strong, thick walls)
through the aorta and its branches (the arteries) to all parts of the
body. The blood returns through the veins to the upper chamber of the
right side (right auricle), passes then to the lower chamber of the
right side (right ventricle), and from this chamber is forced into the
lungs to be oxidized. The openings between the chambers of each side and
into the aorta are guarded by valves.
If the horse is not too fat, one may feel the impact of the apex of the
heart against the chest wall with each contraction of the heart by
placing the hand on the left side back of the fifth rib and above the
point of the elbow. The thinner and the better bred the horse is the
more distinctly this impact is felt. If the animal is excited, or if he
has just been exercised, the impact is stronger than when the horse is
at rest. If the horse is weak, the impact is reduced in force.
The examination of the heart with the ear is an important matter in this
connection. Certain sounds are produced by each contraction of the
normal heart. It is customary to divide these into two, and to call them
the first and second sounds. These two sounds are heard during each
pulsation, and any deviation of the normal indicates some alteration in
the structure or the functions of the heart. In making this examination,
one may apply the left ear over the heavy muscles of the shoulder back
of the shoulder joint, and just above the point of the elbow, or, if the
sounds are not heard distinctly, the left fore leg may be drawn forward
by an assistant and the right ear placed against the lower portion of
the chest wall that is exposed in this manner.
The first sound of the heart occurs while the heart muscle is
contracting and while the blood is being forced from the heart and the
valves are rendered taut to prevent the return of the blood from the
lower to the upper chambers. The second sound follows quickly after the
first and occurs during rebound of blood in the arteries, causing
pressure in the aorta and tensions of the valves guarding its opening
into the left ventricle. The first sound is of a high pitch and is
longer and more distinct than the second. Under the influence of disease
these sounds may be altered in various ways. It is not profitable, in a
work such as this, to describe the details of these alterations. Those
who are interested will find this subject fully discussed in the
veterinary textbooks.
TEMPERATURE.
The temperature of the horse is determined roughly by placing the
fingers in the mouth or between the thighs or by allowing the horse to
exhale against the cheek or back of the hand. In accurate examination,
however, these means of determining temperature are not relied upon, but
recourse is had to the use of the thermometer. The thermometer used for
taking the temperature of a horse is a self-registering clinical
thermometer, similar to that used by physicians, but larger, being from
5 to 6 inches long. The temperature of the animal is measured in the
rectum.
The normal temperature of the horse varies somewhat under different
conditions. It is higher in the young animal than in the old, and is
higher in hot weather than in cold. The weather and exercise decidedly
influence the temperature physiologically. The normal temperature varies
from 99.5 deg. to 101 deg. F. If the temperature rises to 102.5 deg. the horse is
said to have a low fever; if the temperature reaches 104 deg. the fever is
moderate; if it reaches 106 deg. it is high, and above this point it is
regarded as very high. In some diseases, such as tetanus or sunstroke,
the temperature goes as high as 108 deg. or 110 deg.. In the ordinary infectious
diseases it does not often exceed 106 deg.. A temperature of 107.5 deg. and
above is very dangerous and must be reduced promptly if the horse is to
be saved.
THE ORGANS OF RESPIRATION.
In examining this system of organs and their functions it is customary
to begin by noting the frequency of the respiratory movements. This
point can be determined by observing the motions of the nostrils or of
the flanks; on a cold day one can see the condensation of the moisture
of the warm air as it comes from the lungs. The normal rate of
respiration for a healthy horse at rest is from 8 to 16 per minute. The
rate is faster in young animals than in old, and is increased by work,
hot weather, overfilling of the stomach, pregnancy, lying upon the side,
etc. Acceleration of the respiratory rate where no physiological cause
operates is due to a variety of conditions. Among these is fever;
restricted area of active lung tissue, from filling of portions of the
lungs with inflammatory exudate, as in pneumonia; compression of the
lungs or loss of elasticity; pain in the muscles controlling the
respiratory movements; excess of carbon dioxid in the blood; and
constriction of the air passages leading to the lungs.
Difficult or labored respiration is known as dyspnea. It occurs when it
is difficult, for any reason, for the animal to obtain the amount of
oxygen that it requires. This may be due to filling of the lungs, as in
pneumonia; to painful movements of the chest, as in rheumatism or
pleurisy; to tumors of the nose and paralysis of the throat, swellings
of the throat, foreign bodies, or weakness of the respiratory passages,
fluid in the chest cavity, adhesions between the lungs and chest walls,
loss of elasticity of the lungs, etc. Where the difficulty is great the
accessory muscles of respiration are brought into play. In great dyspnea
the horse stands with his front feet apart, with his neck straight out,
and his head extended upon his neck. The nostrils are widely dilated,
the face has an anxious expression, the eyeballs protrude, the
up-and-down motion of the larynx is aggravated, the amplitude of the
movement of the chest walls increased, and the flanks heave.
The expired air is of about the temperature of the body. It contains
considerable moisture, and it should come with equal force from each
nostril and should not have an unpleasant odor. If the stream of air
from one nostril is stronger than from the other, there is an indication
of an obstruction in a nasal chamber. If the air possesses a bad odor,
it is usually an indication of putrefaction of a tissue or secretion in
some part of the respiratory tract. A bad odor is found where there is
necrosis of the bone in the nasal passages or in chronic catarrh. An
ulcerating tumor of the nose or throat may cause the breath to have an
offensive odor. The most offensive breath occurs where there is
necrosis, or gangrene, of the lungs.
In some diseases there is a discharge from the nose. In order to
determine the significance of the discharge it should be examined
closely. One should ascertain whether it comes from one or both
nostrils. If but from one nostril, it probably originates in the head.
The color should be noted. A thin, watery discharge may be composed of
serum, and it occurs in the earlier stages of coryza, or nasal catarrh.
An opalescent, slightly tinted discharge is composed of mucus and
indicates a little more severe irritation. If the discharge is sticky
and puslike, a deeper difficulty or more advanced irritation is
indicated. If the discharge contains flakes and clumps of more or less
dried, agglutinated particles, it is probable that it originates within
a cavity of the head, as the sinuses or guttural pouches. The discharge
of glanders is of a peculiar sticky nature and adheres tenaciously to
the wings of the nostrils. The discharge of pneumonia is of a somewhat
red or reddish brown color and, on this account has been described as a
prune-juice discharge. The discharge may contain blood. If the blood
appears as clots or as streaks in the discharge, it probably originates
at some point in the upper part of the respiratory tract. If the blood
is in the form of a fine froth, it comes from the lungs.
In examining the interior of the nasal passage one should remember that
the normal color of the mucous membrane is a rosy pink and that its
surface is smooth. If ulcers, nodules, swellings, or tumors are found,
these indicate disease. The ulcer that is characteristic of glanders is
described fully in connection with the discussion of that disease.
Between the lower jaws there are several clusters of lymphatic glands.
These glands are so small and so soft that it is difficult to find them
by feeling through the skin, but when a suppurative disease exists in
the upper part of the respiratory tract these glands become swollen and
easy to feel. They may become soft and break down and discharge as
abscesses; this is seen constantly in strangles. On the other hand, they
may become indurated and hard from the proliferation of connective
tissue and attach themselves to the jawbone, to the tongue, or to the
skin. This is seen in chronic glanders. If the glands are swollen and
tender to pressure, it indicates that the disease causing the
enlargement is acute; if they are hard and insensitive, the disease
causing the enlargement is chronic.
The manner in which the horse coughs is of importance in diagnosis. The
cough is a forced expiration, following immediately upon a forcible
separation of the vocal cords. The purpose of the cough is to remove
some irritant substance from the respiratory passages, and it occurs
when irritant gases, such as smoke, ammonia, sulphur vapor, or dust,
have been inhaled. It occurs from inhalation of cold air if the
respiratory passages are sensitive from disease. In laryngitis,
bronchitis, and pneumonia, cough is very easily excited and occurs
merely from accumulation of mucus and inflammatory product upon the
irritated respiratory mucous membrane. If one wishes to determine the
character of the cough, it can easily be excited by pressing upon the
larynx with the thumb and finger. The larynx should be pressed from side
to side and the pressure removed the moment the horse commences to
cough. A painful cough occurs in pleurisy, also in laryngitis,
bronchitis, and bronchial pneumonia. Pain is shown by the effort the
animal exerts to repress the cough. The cough is not painful, as a rule,
in the chronic diseases of the respiratory tract. The force of the cough
is considerable when it is not especially painful and when the lungs are
not seriously involved. When the lungs are so diseased that they can not
be filled with a large volume of air, and in heaves, the cough is weak,
as it is also in weak, debilitated animals. If mucus or pus is coughed
out, or if the cough is accompanied by a gurgling sound, it is said to
be moist; it is dry when these characteristics are not present--that is,
when the air in passing out passes over surface not loaded with
secretion.
In the examination of the chest we resort to percussion and
auscultation. When a cask or other structure containing air is tapped
upon, or percussed, a hollow sound is given forth. If the cask contains
fluid, the sound is of a dull and of quite a different character.
Similarly, the amount of air contained in the lungs can be estimated by
tapping upon, or percussing, the walls of the chest. Percussion is
practiced with the fingers alone or with the aid of a special percussion
hammer and an object to strike upon known as a pleximeter. If the
fingers are used, the middle finger of the left hand should be pressed
firmly against the side of the horse and should be struck with the ends
of the fingers of the right hand bent at a right angle so as to form a
hammer. The percussion hammer sold by instrument makers is made of
rubber or has a rubber tip, so that when the pleximeter, which is placed
against the side, is struck the impact will not be accompanied by a
noise. After experience in this method of examination one can determine
with a considerable degree of accuracy whether the lung contains a
normal amount of air or not. If, as in pneumonia, air has been displaced
by inflammatory product occupying the air space, or if fluid collects in
the lower part of the chest, the percussion sound becomes dull. If, as
in emphysema, or in pneumothorax, there is an excess of air in the
chest cavity, the percussion sound becomes abnormally loud and clear.
Auscultation consists in the examination of the lungs with the ear
applied closely to the chest wall. As the air goes in and out of the
lungs a certain soft sound is made which can be heard distinctly,
especially upon inspiration. This sound is intensified by anything that
accelerates the rate of respiration, such as exercise. This soft,
rustling sound is known as vesicular murmur, and wherever it is heard it
signifies that the lung contains air and is functionally active. The
vesicular murmur is weakened when there is an inflammatory infiltration
of the lung tissue or when the lungs are compressed by fluid in the
chest cavity. The vesicular murmur disappears when air is excluded by
the accumulation, of inflammatory product, as in pneumonia, and when the
lungs are compressed by fluid in the chest cavity. The vesicular murmur
becomes rough and harsh in the early stages of inflammation of the
lungs, and this is often the first sign of the beginning of pneumonia.
By applying the ear over the lower part of the windpipe in front of the
breastbone a somewhat harsh, blowing sound may be heard. This is known
as the bronchial murmur and is heard in normal conditions near the lower
part of the trachea and to a limited extent in the anterior portions of
the lungs after sharp exercise. When the bronchial murmur is heard over
other portions of the lungs, it may signify that the lungs are more or
less solidified by disease and the blowing bronchial murmur is
transmitted through this solid lung to the ear from a distant part of
the chest. The bronchial murmur in an abnormal place signifies that
there exists pneumonia or that the lungs are compressed by fluid in the
chest cavity.
Additional sounds are heard in the lungs in some diseased conditions.
For example, when fluid collects in the air passages and the air is
forced through it or is caused to pass through tubes containing
secretions or pus. Such sounds are of a gurgling or bubbling nature and
are known as mucous rales. Mucous rales are spoken of as being large or
small as they are distinct or indistinct, depending upon the quantity of
fluid that is present and the size of the tube in which this sound is
produced. Mucous rales occur in pneumonia after the solidified parts
begin to break down at the end of the disease. They occur in bronchitis
and in tuberculosis, where there is an excess of secretion.
Sometimes a shrill sound is heard, like the note of a whistle, fife, or
flute. This is due to a dry constriction of the bronchial tubes and it
is heard in chronic bronchitis and in tuberculosis.
A friction sound is heard in pleurisy. This is due to the rubbing
together of roughened surfaces, and the sound produced is similar to a
dry rubbing sound that is caused by rubbing the hands together or by
rubbing upon each other two dry, rough pieces of leather.
THE EXAMINATION OF THE DIGESTIVE TRACT.
The first point in connection with the examination of the organs of
digestion is the appetite and the manner of taking food and drink. A
healthy animal has a good appetite. Loss of appetite does not point to a
special diseased condition, but comes from a variety of causes. Some of
these causes, indeed, may be looked upon as being physiological.
Excitement, strange surroundings, fatigue, and hot weather may all cause
loss of appetite. Where there is cerebral depression, fever, profound
weakness, disorder of the stomach, or mechanical difficulty in chewing
or swallowing, the appetite is diminished or destroyed. Sometimes there
is an appetite or desire to eat abnormal things, such as dirty bedding,
roots of grass, soil, etc. This desire usually comes from a chronic
disturbance of nutrition.
Thirst is diminished in a good many mild diseases unaccompanied by
distinct fever. It is seen where there is great exhaustion or depression
or profound brain disturbance. Thirst is increased after profuse
sweating, in diabetes, diarrhea, in fever, at the crises of infectious
diseases, and when the mouth is dry and hot.
Some diseases of the mouth or throat make it difficult for the horse to
chew or swallow his feed. Where difficulty in this respect is
experienced, the following named conditions should be borne in mind and
carefully looked for: Diseases of the teeth, consisting in decay,
fracture, abscess formation, or overgrowth; inflammatory conditions, or
wounds or tumors of the tongue, cheeks, or lips; paralysis of the
muscles of chewing or swallowing; foreign bodies in upper part of the
mouth between the molar teeth; inflammation of throat. Difficulty in
swallowing is sometimes shown by the symptom known as "quidding."
Quidding consists in dropping from the mouth well-chewed and insalivated
boluses of feed. A mouthful of hay, for example, after being ground and
masticated, is carried to the back part of the mouth. The horse then
finds that from tenderness of the throat, or from some other cause,
swallowing is difficult or painful, and the bolus is then dropped from
the mouth. Another quantity of hay is similarly prepared, only to be
dropped in turn. Sometimes quidding is due to a painful tooth, the bolus
being dropped from the mouth when the tooth is struck and during the
pang that follows. Quidding may be practiced so persistently that a
considerable pile of boluses of feed accumulate in the manger or on the
floor of the stall. In pharyngitis one of the symptoms is a return
through the nose of fluid that the horse attempts to swallow.
In some brain diseases, and particularly in chronic internal
hydrocephalus, the horse has a most peculiar manner of swallowing and of
taking feed. A similar condition is seen in hyperemia of the brain. In
eating the horse will sink his muzzle into the grain in the feed box
and eat for a while without raising the head. Long pauses are made while
the feed is in the mouth. Sometimes the horse will eat very rapidly for
a little while and then slowly; the jaws may be brought together so
forcibly that the teeth gnash. In eating hay the horse will stop at
times with hay protruding from the mouth and stand stupidly, as though
he has forgotten what he was about.
In examining the mouth one should first look for swellings or for
evidence of abnormal conditions upon the exterior; that is, the front
and sides of the face, the jaws, and about the muzzle. By this means
wounds, fractures, tumors, abscesses, and disease accompanied by
eruptions about the muzzle may be detected. The interior of the mouth is
examined by holding the head up and inserting the fingers through the
interdental space in such a way as to cause the mouth to open. The
mucous membrane should be clean and of a light-pink color, excepting on
the back of the tongue, where the color is a yellowish gray. As
abnormalities of this region, the chief are diffuse inflammation,
characterized by redness and catarrhal discharge; local inflammation, as
from eruptions, ulcers, or wounds; necrosis of the lower jawbone in
front of the first back tooth; and swellings. Foreign bodies are
sometimes found embedded in the mucous membrane lining of the mouth or
lodged between the teeth.
The examination of the pharynx and of the esophagus is made chiefly by
pressing upon the skin covering these organs in the region of the throat
and along the left side of the neck in the jugular gutter. Sometimes,
when a more careful examination is necessary, an esophageal tube or
probang is passed through the nose or mouth down the esophagus to the
stomach.
Vomiting is an act consisting in the expulsion of all or part of the
contents of the stomach through the mouth or nose. This act is more
difficult for the horse than for most of the other domestic animals,
because the stomach of the horse is small and does not lie on the floor
of the abdominal cavity, so that the abdominal walls in contracting do
not bring pressure to bear upon it so directly and forcibly, as is the
case in many other animals. Beside this, there is a loose fold of mucous
membrane at the point where the esophagus enters the stomach, and this
forms a sort of valve which does not interfere with the passage of food
into the stomach, but does interfere with the exit of food through the
esophageal opening. Still, vomiting is a symptom that is occasionally
seen in the horse. It occurs when the stomach is very much distended
with food or with gas. Distention stretches the mucous membrane and
eradicates the valvular fold referred to, and also makes it possible for
more pressure to be exerted upon the stomach through the contraction of
the abdominal muscles. Since the distention to permit vomiting must be
extreme, it not infrequently happens that it leads to rupture of the
stomach walls. This has caused the impression in the minds of some that
vomiting can not occur in the horse without rupture of the stomach, but
this is incorrect, since many horses vomit and afterwards become
entirely sound. After rupture of the stomach has occurred vomiting is
impossible.
In examination of the abdomen one should remember that its size depends
largely upon the breed, sex, and conformation of the animal, and also
upon the manner in which the animal has been fed and the use to which it
has been put. A pendulous abdomen may be the result of an abdominal
tumor or of an accumulation of fluid in the abdominal cavity; or, on the
other hand, it may merely be an indication of pregnancy, or of the fact
that the horse has been fed for a long time on bulky and innutritious
food. Pendulous abdomen occurring in a work horse kept on a concentrated
diet is an abnormal condition. The abdomen may increase suddenly in
volume from accumulation of gas in tympanic colic. The abdomen becomes
small and the horse is said to be "tucked up" from long-continued poor
appetite, as in diseases of the digestive tract and in fever. This
condition also occurs in tetanus from the contraction of the abdominal
walls and in diarrhea from emptiness.
In applying the ear to the flank, on either the right or left side,
certain bubbling sounds may be heard that are known as peristaltic
sounds, because they are produced by peristalsis, or wormlike
contraction of the intestines. These sounds are a little louder on the
right side than on the left on account of the fact that the large
intestines lie in the right flank. Absence of peristaltic sounds is
always an indication of disease, and suggests exhaustion or paralysis of
the intestines. This may occur in certain kinds of colic and is an
unfavorable symptom. Increased sounds are heard where the intestines are
contracted more violently than in health, as in spasmodic colic, and
also where there is an excess of fluid or gas in the intestinal canal.
The feces show, to a certain extent, the thoroughness of digestion. They
should show that the feed has been well ground, and should, in the
horse, be free from offensive odor or coatings of mucus. A coating of
mucus shows intestinal catarrh. Blood on the feces indicates severe
inflammation. Very light color and bad odor may come from inactive
liver. Parasites are sometimes in the dung.
Rectal examination consists in examination of the organs of the pelvic
cavity and posterior portion of the abdominal cavity by the hand
inserted into the rectum. This examination should be attempted by a
veterinarian only, and is useless except to one who has a good knowledge
of the anatomy of the parts concerned.
THE EXAMINATION OF THE NERVOUS SYSTEM.
The great brain, or cerebrum, is the seat of intelligence, and it
contains the centers that control motion in many parts of the body. The
front portion of the brain is believed to be the region that is most
important in governing the intelligence. The central and posterior
portions of the cerebrum contain the centers for the voluntary motions
of the face and of the front and hind legs. The growth of a tumor or an
inflammatory change in the region of a center governing the motion of a
certain part of the body has the effect of disturbing motion in that
part by causing excessive contraction known as cramps, or inability of
the muscles to contract, constituting the condition known as paralysis.
The nerve paths from the cerebrum, and hence from these centers to the
spinal cord and thence to the muscles, pass beneath the small brain, or
the cerebellum, and through the medulla oblongata to the spinal cord.
Interference with these paths has the effect of disturbing motion of the
parts reached by them. If all of the paths on one side are interfered
with, the result is paralysis of one side of the body.
The small brain, or cerebellum, governs the regularity, or coordination,
of movements. Disturbances of the cerebellum cause a tottering,
uncertain gait. In the medulla oblongata, which lies between the spinal
cord and the cerebellum, are the centers governing the circulation and
breathing.
The spinal cord carries sensory messages to the brain and motor
impressions from the brain. The anterior portions of the cord contain
the motor paths, and the posterior portions of the cord contain the
sensory paths.
Paralysis of a single member or a single group of muscles is known as
monoplegia and results from injury to the motor center or to a nerve
trunk leading to the part that is involved. Paralysis of one-half of the
body is known as hemiplegia and results from destruction or severe
disturbances of the cerebral hemisphere of the opposite side of the body
or from interference with nerve paths between the cerebellum, or small
brain, and the spinal cord. Paralysis of the posterior half of the body
is known as paraplegia and results from derangement of the spinal cord.
If the cord is pressed upon, cut, or injured, messages can not be
transmitted beyond that point, and so the posterior part becomes
paralyzed. This is seen when the back is fractured.
Abnormal mental excitement may be due to congestion of the brain or to
inflammation. The animal so afflicted becomes vicious, pays no attention
to commands, cries, runs about in a circle, stamps with the feet,
strikes, kicks, etc. This condition is usually followed by a dull,
stupid state, in which the animal stands with his head down, dull and
irresponsive to external stimuli. Cerebral depression also occurs in the
severe febrile infectious diseases, in chronic hydrocephalus, in chronic
diseases of the liver, in poisoning with a narcotic substance, and with
chronic catarrh of the stomach and intestines.
Fainting is a symptom that is not often seen in horses. When it occurs
it is shown by unsteadiness of gait, tottering, and, finally, inability
to stand. The cause usually lies in a defect of the small brain, or
cerebellum. This defect may be merely in respect of the blood supply, to
congestion, or to anemia, and in this case it is likely to pass away and
may never return, or it may be due to some permanent cause, as a tumor
or an abscess, or it may result from a hemorrhage, from a defect of the
valves of the heart, or from poisoning.
Loss of consciousness is known as coma. It is caused by hemorrhage in
the brain, by profound exhaustion, or may result from a saturation of
the system with the poison of some disease. Coma may follow upon
cerebral depression, which occurs as a secondary state of inflammation
of the brain.
Where the sensibility of a part is increased the condition is known as
hyperesthesia, and where it is lost--that is, where there is no feeling
or knowledge of pain--the condition is known as anesthesia. The former
usually accompanies some chronic disease of the spinal cord or the
earlier stages of irritation of a nerve trunk. Hyperesthesia is
difficult to detect in a nervous, irritable animal, and sometimes even
in a horse of less sensitive temperament. An irritable, sensitive spot
may be found surrounded by skin that is not sensitive to pressure. This
is sometimes a symptom of beginning of inflammation of the brain.
Anesthesia occurs in connection with cerebral and spinal paralysis,
section of a nerve trunk leading to a part, in severe mental depression,
and in narcotic poisoning.
URINARY AND SEXUAL ORGANS.
In considering the examination of the urinary and sexual organs we may
consider, at the beginning, a false impression that prevails to an
astonishing extent. Many horsemen are in the habit of pressings upon the
back of a horse over the loins or of sliding the ends of the fingers
along on either side of the median line of this region. If the horse
depresses his back it is at once said "his kidneys are weak." Nothing
could be more absurd or further from the truth. Any healthy horse--any
horse with normal sensation and with a normally flexible back--will
cause it to sink when manipulated in this way. If the kidneys are
inflamed and sensitive, the back is held more rigidly and is not
depressed under this pressure.
To examine the kidneys by pressure the pressure should be brought to
bear over these organs. The kidneys lie beneath the ends of the
transverse processes of the vertebrae of the loins and beneath the
hind-most ribs. If the kidneys are actually inflamed and especially
sensitive, pressure or light blows applied here may cause the horse to
shrink.
The physical examination of the sexual and generative organs is made in
large part through the rectum, and this portion of the examination
should be carried out by a veterinarian only. By this means it is
possible to discover or locate cysts of the kidneys, urinary calculi in
the ureters, bladder, or upper urethra, malformations, and acute
inflammations accompanied by pain. The external genital organs are
swollen, discolored, or show a discharge as a result of local disease or
from disease higher in the tract.
The manner of urinating is sometimes of considerable diagnostic
importance. Painful urination is shown by frequent attempts, during
which but a small quantity of urine is passed; by groaning, by
constrained attitude, etc. This condition comes from inflammation of the
bladder or urethra, urinary calculi (stones of the bladder or urethra),
hemorrhage, tumors, bruises, etc. The urine is retained from spasms of
the muscle at the neck of the bladder, from calculi, inflammatory
growths, tumors, and paralysis of the bladder.
The urine dribbles without control when the neck of the bladder is
weakened or paralyzed. This condition is seen after the bladder is
weakened from long-continued retention and where there is a partial
paralysis of the hind quarters.
Horses usually void urine five to seven times a day, and pass from 4 to
7 quarts. Disease may be shown by increase in the number of voidings or
of the quantity. Frequent urination indicates an irritable or painful
condition of the bladder or urethra or that the quantity is excessive.
In one form of chronic inflammation of the kidneys (interstitial
nephritis) and in polyuria the quantity may be increased to 20 or 30
quarts daily. Diminution in the quantity of urine comes from profuse
sweating, diarrhea, high fever, weak heart, diseased and nonsecreting
kidneys, or an obstruction to the flow.
The urine of the healthy horse is a pale or at times a slightly reddish
yellow. The color is less intense when the quantity is large, and is
more intense when the quantity is diminished. Dark-brown urine is seen
in azoturia and in severe acute muscular rheumatism. A brownish-green
color is seen in jaundice. Red color indicates admixture of blood from a
bleeding point at some part of the urinary tract, usually in the
kidneys.
The urine of the healthy horse is not clear and transparent. It contains
mucus, which causes it to be slightly thick and stringy, and a certain
amount of undissolved carbonates, causing it to be cloudy. A sediment
collects when the urine is allowed to stand. The urine of the horse is
normally alkaline. If it becomes acid the bodies in suspension are
dissolved and the urine is made clear. The urine may be unusually cloudy
from the addition of abnormal constituents, but to determine their
character a chemical or microscopic examination is necessary. Red or
reddish flakes or clumps in the urine are always abnormal, and denote a
hemorrhage or suppuration in the urinary tract.
The normal specific gravity of the urine of the horse is about 1.040. It
is increased when the urine is scanty and decreased when the quantity is
excessive.
Acid reaction of the urine occurs in chronic intestinal catarrh, in high
fever, and during starvation. Chemical and microscopic tests and
examinations are often of great importance in diagnosis, but require
special apparatus and skill.
Other points in the examination of a sick horse require more discussion
than can be afforded in this connection, and require special training on
the part of the examiner. Among such points may be mentioned the
examination of the organs of special sense, the examination of the
blood, the microscopic examination of the secretions and excretions,
bacteriological examinations of the secretions, excretions, and tissues,
specific reaction tests, and diagnostic inoculation.
FUNDAMENTAL PRINCIPLES OF DISEASE.
By RUSH SHIPPEN HUIDEKOPER, M. D., VET.
[Revised by Leonard Pearson, B. S., V. M. D.]
ANIMAL TISSUES.
The nonprofessional reader may regard the animal tissues, which are
subject to inflammation, as excessively simple structures, as similar,
simple, and fixed in their organization as the joists and boards which
frame a house, the bricks and iron coils of pipe which build a furnace,
or the stones and mortar which make the support of a great railroad
bridge. Yet while the principles of structure are thus simple, for the
general understanding by the student who begins their study the complete
appreciation of the shades of variation, which differentiate one tissue
from another, which define a sound tendon or a ligament from a fibrous
band--the result of disease filling in an old lesion and tying one organ
with another--is as complicated as the nicest jointing of Chinese
woodwork, the building of a furnace for the most difficult chemical
analysis, or the construction of a bridge which will stand for ages and
resist any force or weight.
All tissues are composed of certain fundamental and similar elements
which are governed by the same rules of life, though at first glance
they may appear to be widely different. These are (a) amorphous
substances, (b) fibers, and (c) cells.
(a) Amorphous substances may be in liquid form, as in the fluid of the
blood, which holds a vast amount of salts and nutritive matter in
solution; or they may be in a semiliquid condition, as the plasma which
infiltrates the loose meshes of connective tissue and lubricates the
surface of some membranes; or they may be in the form of a glue or
cement, fastening one structure to another, as a tendon or muscle end to
a bone; or, again, they hold similar elements firmly together, as in
bone, where they form a stiff matrix which becomes impregnated with lime
salts. Amorphous substances, again, form the protoplasm or nutritive
element of cells or the elements of life.
(b) Fibers are formed of elements of organic matter which have only a
passive function. They can be assimilated to little strings, or cords,
tangled one with another like a mass of waste yarn, woven regularly like
a cloth, or bound together like a rope. They are of two kinds--white
connective tissue fibers, only slightly extensible, pliable, and very
strong, and yellow elastic fibers, elastic, curly, ramified, and very
dense. These fibers once created require the constant presence of fluids
around them in order to retain their functional condition, as a piece of
harness leather demands continual oiling to keep its strength, but they
undergo no change or alteration in their form until destroyed by death.
(c) Cells, which may even be regarded as low forms of life, are masses
of protoplasm or amorphous living matter, with a nucleus and frequently
a nucleolus, which are capable of assimilating nutriment or food,
propagating themselves either into others of the same form or into fixed
cells of another outward appearance and different function but of the
same constitution. It is simply in the mode of the grouping of these
elements that we have the variation in tissues, as (1) loose connective
tissue, (2) aponeurosis and tendons, (3) muscles, (4) cartilage, (5)
bones, (6) epithelia and endothelia, (7) nerves.
(1) Loose connective tissue forms the great framework, or scaffolding,
of the body, and is found under the skin, between the muscles
surrounding the bones and blood vessels, and entering into the
structures of almost all the organs. In this the fibers are loosely
meshed together like a sponge, leaving spaces in which the nutrient
fluid and cells are irregularly distributed. This tissue we find in the
skin, in the spaces between the organs of the body where fat
accumulates, and as the framework of all glands.
(2) Aponeurosis and tendons are structures which serve for the
termination of muscles and for their contention, and for the attachment
of bones together. In these the fibers are more frequent and dense, and
are arranged with regularity, either crossing each other or lying
parallel, and here the cells are found in minimum quantity.
(3) In the muscles the cells lie end to end, forming long fibers which
have the power of contraction, and the connective tissue is in small
quantity, serving the passive purpose of a band around the contractile
elements.
(4) In cartilage a mass of firm amorphous substance, with no vascularity
and little vitality, forms the bed for the chondroplasts, or cells of
this tissue.
(5) Bone differs from the above in having the amorphous matter
impregnated with lime salts, which gives it its rigidity and firmness.
(6) Epithelia and endothelia, or the membranes which cover the body and
line all its cavities and glands, are made up of single or stratified
and multiple layers of cells bound together by a glue of amorphous
substance and resting on a layer composed of fibers. When the membrane
serves for secreting or excreting purposes, as in the salivary glands or
the kidneys, it is usually simple; when it serves the mechanical purpose
of protecting a part, as over the tongue or skin, it is invariably
multiple and stratified, the surface wearing away while new cells
replace it from beneath.
(7) In nerves, stellate cells are connected by their rays to each other,
or to fibers which conduct the nerve impressions, or they act as
receptacles, storehouses, and transmitters for them, as the switch-board
of a telephone system serves to connect the various wires.
All these tissues are supplied with blood in greater or less quantity.
The vascularity depends upon the function which the tissue is called
upon to perform. If this is great, as in the tongue, the lungs, or the
sensitive part of the hoof, a large quantity of blood is required; if
the labor is a passive one, as in cartilage, the membrane over the
withers, or the tendons of the legs, the vessels only reach the
periphery, and nutrition is furnished by imbibition of the fluids
brought to their surface by the blood vessels.
Blood is brought to the tissues by arterioles, or the small terminations
of the arteries, and is carried off from them by the veinlets, or the
commencement of the veins. Between these two systems are small, delicate
networks of vessels called capillaries, which subdivide into a veritable
lacework so as to reach the neighborhood of every element.
In health the blood passes through these capillaries with a regular
current, the red cells or corpuscles floating rapidly in the fluid in
the center of the channel, while the white or ameboid cells are
attracted to the walls of the vessels and move very slowly. The supply
of blood is regulated by the condition of repose or activity of the
tissue, and under normal conditions the outflow exactly compensates the
supply. The caliber of the blood vessels, and consequently the quantity
of blood which they carry, is governed by nerves of the sympathetic
system in a healthy body with unerring regularity, but in a diseased
organ the flow may cease or be greatly augmented. In health a tissue or
organ receives its proper quantity of blood; the nutritive elements are
extracted for the support of the tissue and for the product, which the
function of the organ forms. The force required in the achievement of
this is furnished by combustion of the hydrocarbons and oxygen brought
by the arterial blood, then by the veins this same fluid passes off,
less its oxygen, loaded with the waste products, which are the result of
the worn-out and disintegrated tissues, and of those which have
undergone combustion. The foregoing brief outline indicates the process
of nutrition of the tissues.
Hypernutrition, or excessive nutrition of a tissue, may be normal or
morbid. If the latter, the tissue becomes congested or inflamed.
CONGESTION.
Congestion is an unnatural accumulation of blood in a part. Excessive
accumulation of blood may be normal, as in blushing or in the red face
which temporarily follows a violent muscular effort, or, as in the
stomach or liver during digestion, or in the lungs after severe work,
from which, in the latter case, it is shortly relieved by a little rapid
breathing. The term congestion, however, usually indicates a morbid
condition, with more or less lasting effects. Congestion is active or
passive. The former is produced by an increased supply of blood to the
part, the latter by an obstacle preventing the escape of blood from the
tissue. In either case there is an increased supply of blood, and as a
result increased combustion and augmented nutrition.
ACTIVE CONGESTION.
Active congestion is caused by--
(1) _Functional activity._--Any organ which is constantly or excessively
used is habituated to hold an unusual quantity of blood; the vessels
become dilated; if overstrained the walls become weakened, lose their
elasticity, and any sudden additional quantity of blood engorges the
tissues so that they can not contract, and congestion results. Example:
The lungs of a race horse, after an unusual burst of speed or severe
work, in damp weather.
(2) _Irritants._--Heat and cold, chemical or mechanical. Any of these,
by threatening the vitality of a tissue, induce immediately an augmented
flow of blood to the part to furnish the means of repair--a hot iron,
frostbites, acids, or a blow.
(3) _Nerve influence._--This may produce congestion either by acting on
the part reflexly or as the result of some central nerve disturbance
affecting the branch which supplies a given organ.
(4) _Plethora and sanguinary temperament._--Full-blooded animals are
much more predisposed to congestive diseases than those of a lymphatic
character or those in an anemic condition. The circulation in them is
forced to all parts with much greater force and in large quantities. A
well-bred, full-blooded horse is much more subject to congestive
diseases than a common, coarse, or old, worn-out animal.
(5) _Fevers._--In fever the heart works more actively and forces the
current of blood more rapidly; the tissues are weakened, and it requires
but a slight local cause at any part to congest the structures already
overloaded with blood. Again, in certain fevers, we find alteration of
the blood itself, rendering it less or more fluid, which interferes with
its free passage through the vessels and induces a local predisposition
to congestion.
(6) _Warm climate and summer heat._--Warmth of the atmosphere relaxes
the tissues; it demands of the animals less blood to keep up their own
body temperature, and the extra quantity accumulates in the blood-vessel
system. It causes sluggishness in the performance of the organic
functions, and in this way it induces congestion, especially of the
internal organs. So we find founders, congestive colics, and staggers
more frequent in summer than in winter.
(7) _Previous congestion._--Whether the previous congestion of any organ
has been a continuous normal one--that is, a repeated functional
activity--or has been a morbid temporary overloading, it always leaves
the walls of the vessels weakened and more predisposed to recurrent
attacks from accidental causes than are perfectly healthy tissues. Thus
a horse which has had a congestion of the lungs from a severe drive is
liable to have another attack from even a lesser cause.
The alterations of congestion are distention of the blood vessels,
accumulation of the cellular elements of the blood in them, and effusion
of a portion of the liquid of the blood into the fibrous tissues which
surround the vessels. When the changes produced by congestion are
visible, as in the eye, the nostril, the mouth, the genital organs, and
on the surface of the body in white or unpigmented animals, the part
appears red from the increase of blood; it becomes swollen from the
effusion of liquid into the spongelike connective tissues; it is at
times more or less hot from the increased combustion; the part is
frequently painful to the animal from pressure of the effusion on the
nerves, and the function of the tissue is interfered with. The secretion
or excretion of glands may be augmented or diminished. Muscles may be
affected with spasms or may be unable to contract. The eyes and ears may
be affected with imaginary sights and sounds.
PASSIVE CONGESTION.
Passive congestion is caused by interference with the return of the
current of blood from a part.
Old age and debility weaken the tissues and the force of the
circulation, especially in the veins, and retard the movement of the
blood. We then see horses of this class with stocked legs, swelling of
the sheath of the penis or of the milk glands, and of the under surface
of the belly. We find them also with effusions of the liquid parts of
the blood into the lymph spaces of the posterior extremities and organs
of the pelvic cavity.
Tumors or other mechanical obstructions, by pressing on the veins,
retard the flow of blood and cause it to back up in distal parts of the
body causing passive congestion.
The alterations of passive congestion, as in active congestion, consist
of an increased quantity of blood in the vessels and an exudation of
its fluid into the tissues surrounding them, but in passive congestion
we have a dark, thick blood which has lost its oxygen, instead of the
rich, combustible blood rich in oxygen which is found in active
congestion.
The termination of congestion is by resolution or inflammation. In the
first case, the choked-up blood vessels find an outlet for the excessive
quantity of blood and are relieved; the transuded serum or fluid of the
blood is reabsorbed, and the part returns almost to its normal
condition, with, however, a tendency to weakness predisposing to future
trouble of the same kind. In the other case further alterations take
place, and we have inflammation.
INFLAMMATION.
(Plates I and II.)
Inflammation is a hypernutrition of a tissue. It is described by Dr.
Agnew, the surgeon, as "a double-edged sword, cutting either way for
good or for evil." The increased nutrition may be moderate and cause a
growth of new tissue, a simple increase of quantity at first; or it may
produce a new growth differing in quality; or it may be so great that,
like luxuriant, overgrown weeds, the elements die from their very haste
of growth, and we have immediate destruction of the part. According to
the rapidity and intensity of the process of structural changes which
takes place in an inflamed tissue, inflammation is described as acute or
chronic, with a vast number of intermediate forms. When the phenomena
are marked it is termed sthenic; when less distinct, as the result of a
broken-down and feeble constitution in the animal, it is called
asthenic. Certain inflammations are specific, as in strangles, the
horsepox, glanders, etc., where a characteristic or specific cause or
condition is added to the origin, character of phenomena, or alterations
which result from an ordinary inflammation. An inflammation may be
circumscribed or limited, as in the abscess on the neck caused by the
pressure of a collar, in pneumonia, in glanders, in the small tumors of
a splint or a jack; or it may be diffuse, as in severe fistulas of the
withers, in an extensive lung fever, in the legs in a case of grease, or
in the spavins which affect horses with poorly nourished bones. The
causes of inflammation are practically the same as those of congestion,
which is the initial step of all inflammation.
The temperament of a horse predisposes the animal to inflammation of
certain organs. A full-blooded animal, whose veins show on the surface
of the body, and which has a strong, bounding heart pumping large
quantities of blood into the vascular organs like the lungs, the
intestines, and the laminae of the feet, is more liable to have
pneumonia, congestive colics, and founder, than lymphatic, cold-blooded
animals which have pleurisies, inflammation of the bones, spavins,
ringbones, inflammation of the glands of the less vascular skin of the
extremities, greasy heels, thrush, etc.
[Illustration: PLATE I.
INFLAMMATION.
1--_Uninflamed wing of the bat._
2--_Inflamed wing of the bat._]
[Illustration: PLATE II.
INFLAMMATION.
1--_Non-inflamed mesentery of the frog, 400 diameters, reduced 1/2: a,
a, Venule with red and white corpuscles; b, b, Gelatinous nerve fibre;
c, Capillary; d, d, Dark-bordered nerve fibre; e, e, Connective tissue
with connective tissue corpuscles and leucocytes scattered sparsely
through it._
2--_Inflamed mesentery of the frog, 400 diameters, reduced 1/2: a, a,
Venule filled with red and white corpuscles, the red in the centre and
the white crowding along the walls; c, c, Capillary, distended with red
and white corpuscles, number of the white much decreased; d, d,
Connective tissue between venule and capillary filled with migrated
leucocytes; e, e, Connective tissue with less infiltration; f,
Dark-bordered nerve fibre; g, Number of nuclei, in sheaths increased._]
Young horses have inflammation of the membranes lining the air passages
and digestive tract, while older animals are more subject to troubles in
the closed serous sacs and in the bones.
The work to which a horse is put (saddle or harness, speed or draft)
will influence the predisposition of an animal to inflammatory diseases.
As in congestion, the functional activity of a part is an important
factor in localizing this form of disease. Given a group of horses
exposed to the same draft of cold air or other exciting cause of
inflammation, the one which has just been eating will be attacked with
an inflammation of the bowels; the one that has just been working so as
to increase its respiration will have an inflammation of the throat,
bronchi, or lungs; the one that has just been using its feet excessively
will have a founder or inflammation of the laminae of the feet.
The direct cause of inflammation is usually an irritant of some form.
This may be a pathogenic organism--a disease germ--or it may be
mechanical or chemical, external or internal. Cuts, bruises, injuries of
any kind, parasites, acids, blisters, heat, cold, secretions, such as an
excess of tears over the cheek or urine on the legs, all cause
inflammation by direct injury to the part. Strains or wrenches of
joints, ligaments, and tendons cause trouble by laceration of the
tissue.
Inflammations of the internal organs are caused by irritants as above,
and by sudden cooling of the surface of the animal, which drives the
blood to that organ which at the moment is most actively supplied with
blood. This is called repercussion. A horse which has been worked at
speed and is breathing rapidly is liable to have pneumonia if suddenly
chilled, while an animal which has just been fed is more liable to have
a congestive colic if exposed to the same influence, the blood in this
case being driven from the exterior to the intestines, while in the
former it was driven to the lungs.
_Symptoms._--The symptoms of inflammation are, as in congestion, change
of color, due to an increased supply of blood; swelling, from the same
cause, with the addition of an effusion into the surrounding tissues;
heat, owing to the increased combustion in the part; pain, due to
pressure on the nerves, and altered function. This latter may be
augmented or diminished, or first one and then the other. In addition to
the local symptoms, inflammation always produces more or less
constitutional disturbance or fever. A splint or small spavin will cause
so little fever that it is not appreciable, while a severe spavin, an
inflamed joint, or a pneumonia may give rise to a marked fever.
The alterations in an inflamed tissue are first those of congestion,
distention of the blood vessels, and exudation of the fluid of the blood
into the surrounding fibers, with, however, a more nearly complete
stagnation of the blood; fibrin, or lymph, a plastic substance, is
thrown out as well, and the cells, which we have seen to be living
organisms in themselves, no longer carried in the current of the blood,
migrate from the vessels and, finding proper nutriment, proliferate or
multiply with greater or lesser rapidity. The cells which lie dormant in
the meshes of the surrounding fibers are awakened into activity by the
nutritious lymph which surrounds them, and they also multiply.
Whether the cell in an inflamed part is the white ameboid cell of the
blood or the fixed connective tissue embedded in the fibers, it
multiplies in the same way. The nucleus in the center is divided into
two, and then each again into two, ad infinitum. If the process is slow,
each new cell may assimilate nourishment and become, like its ancestor,
an aid in the formation of new tissues; if, however, the changing takes
place rapidly, the brood of young cells have not time to grow or use up
the surrounding nourishment, and, but half developed, they die, and we
then have destruction of tissue, and pus or matter is formed, a material
made up of the imperfect dead elements and the broken-down tissue.
Between the two there is an intermediate form, where we have imperfectly
formed tissues, as in "proud flesh," large, soft splints; fungous
growths, greasy heels, and thrush.
Whether the inflamed tissue is one like the skin, lungs, or intestines,
very loose in their texture, or a tendon or bone, dense in structure,
and comparatively poor in blood vessels, the principle of the process is
the same. The effects, however, and the appearance may be widely
different. After a cut on the face or an exudation into the lungs, the
loose tissues and multiple vessels allow the proliferating cells to
obtain rich nourishment; absorption can take place readily, and the part
regains its normal condition entirely, while a bruise at the heel or at
the withers finds a dense, inextensible tissue where the multiplying
elements and exuded fluids choke up all communication, and the parts die
(necrose) from want of blood and cause a serious quittor, or fistula.
This effect of structure of a part on the same process shows the
importance of a perfect knowledge in the study of a local trouble, and
the indispensable part which such knowledge plays in judging of the
gravity of an inflammatory disease, and in formulating a prognosis or
opinion of the final termination of it. It is this which allows the
veterinarian, through his knowledge of the intimate structure of a part
and the relations of its elements, to judge of the severity of a
disease, and to prescribe different modes of treatment in two animals
for troubles which, to the less experienced observer, appear to be
absolutely identical.
_Termination of inflammation._--Like congestion, inflammation may
terminate by resolution. In this case the exuded lymph undergoes
chemical change, and the products are absorbed and carried off by the
blood vessels and lymphatics, to be thrown out of the body by the
kidneys, liver, the glands of the skin, and the other excretory organs.
The cells, which have wandered into the neighboring tissues from the
blood vessels, gradually disappear or become transformed into fixed
cells. Those which are the result of the tissue cells, wakened into
active life, follow the same course. The vessels themselves contract,
and, having resumed their normal caliber, the part apparently reassumes
its normal condition; but it is always weakened, and a new inflammation
is more liable to reappear in a previously inflamed part than in a sound
one. The alternate termination is necrosis, or mortification. If the
necrosis, or death of a part, is gradual, by small stages, each cell
losing its vitality after the other in more or less rapid succession, it
takes the name of ulceration. If it occurs in a considerable part at
once, it is called gangrene. If this death of the tissues occurs deep in
the organism, and the destroyed elements and proliferated and dead cells
are inclosed in a cavity, the result of the process is called an
abscess. When it occurs on a surface, it is an ulcer, and an abscess by
breaking on the exterior becomes then also an ulcer. Proliferating and
dying cells, and the fluid which exudes from an ulcerating surface and
the debris of broken-down tissue is known as pus, and the process by
which this is formed is known as suppuration. A mass of dead tissue in a
soft part is termed a slough, while the same in bone is called a
sequestrum. Such changes are especially liable to occur when the part
becomes infected with microorganisms that have the property of
destroying tissue and thus causing the production of pus. These are
known as pyogenic microorganisms. There are also bacilli that are
capable of multiplying in tissues and so irritating them as to cause
them to die (necrose) without forming pus.
_Treatment of inflammation._--The study of the causes and pathological
alterations of inflammation has shown the process to be one of
hypernutrition, attended by excessive blood supply, so this study will
indicate the primary factor to be employed in the treatment of it. Any
agent which will reduce the blood supply and prevent the excessive
nutrition of the elements of the part will serve as a remedy. The means
employed may be used locally to the part, or they may be constitutional
remedies, which act indirectly.
_Local treatment._--Removal of the cause will frequently allow the part
to heal at once. Among causes of inflammation may be mentioned a stone
in the frog, causing a traumatic thrush; a badly fitting harness or
saddle, causing ulcers of the skin; decomposing manure and urine in a
stable, which, by their vapors, irritate the air tubes and lungs and
cause a cough.
Motion stimulates the action of the blood, and thus feeds an inflamed
tissue. This is alike applicable to a diseased point irritated by
movement to an inflamed pair of lungs surcharged with blood by the use
demanded of them in a working animal, or to an inflamed eye exposed to
light, or an inflamed stomach and intestines still further fatigued by
feed. Rest, absolute quiet, a dark stable, and small quantities of
easily digested feed will often cure serious inflammatory troubles
without further treatment.
The application of ice bags or cold water by bandages, douching with a
hose, or irrigation with dripping water, contracts the blood vessels,
acts as a sedative to the nerves, and lessens the vitality of a part; it
consequently prevents the tissue change which inflammation produces.
Either dry or moist heat acts as a derivative. It quickens the
circulation and renders the chemical changes more active in the
surrounding parts; it softens the tissues and attracts the current of
blood from the inflamed organ; it also promotes the absorption of the
effusion and hastens the elimination of the waste products in the part.
Heat may be applied by hand rubbing or active friction and the
application of warm coverings (bandages) or by cloths wrung out of warm
water; or steaming with warm, moist vapor, medicated or not, will answer
the same purpose. The latter is especially applicable to inflammatory
troubles in the air passages.
Local bleeding frequently affords immediate relief by carrying off the
excessive blood and draining the effusion which has already occurred. It
affords direct mechanical relief, and, by a stimulation of the part,
promotes the chemical changes necessary for bringing the diseased
tissues to a healthy condition. Local blood-letting can be done by
scarifying, or making small punctures into the inflamed part, as in the
eyelid of an inflamed eye, or into the sheath of the penis, or into the
skin of the latter organ when congested, or the leg when acutely
swelled.
Counterirritants are used for deep inflammations. They act by bringing
the blood to the surface and consequently lessening the blood pressure
within. The derivation of the blood to the exterior diminishes the
amount in the internal organs and is often very rapid in its action in
relieving a congested lung or liver. The most common counterirritant is
mustard flour. It is applied as a soft paste mixed with warm water to
the under surface of the belly and to the sides, where the skin is
comparatively soft and vascular. Colds in the throat or inflammations at
any point demand the treatment applied in the same manner to the belly
and sides and not to the throat or on the legs, as so often used.
Blisters, iodin, and many other irritants are used in a similar way.
_Constitutional treatment_ in inflammation is designed to reduce the
current of blood, which is the fuel for the inflammation in the diseased
part, to quiet the patient, and to combat the fever or general effects
of the trouble in the system, and to favor the neutralization or
elimination of the products of the inflammation.
Reduction of blood is obtained in various ways. The diminution of the
quantity of the blood lessens the amount of pressure on the vessels,
and, as a sequel, the volume of it which is carried to the point of
inflammation; it diminishes the body temperature or fever; it numbs the
nervous system, which plays an important part as a conductor of
irritation in diseases.
Blood-letting is the most rapid means, and frequently acts like a charm
in relieving a commencing inflammatory trouble. One must remember,
however, that the strength of the body and repair depend on the blood;
hence blood-letting should be practiced only in full-blooded,
well-nourished animals and in the early stages of the disease.
Cathartics act by drawing off a large quantity of fluid from the blood
through the intestines, and have the advantage over the last remedy of
removing only the watery and not the formed elements from the
circulation. The blood cells remain, leaving the blood as rich as it was
before. Again, the glands of the intestines are stimulated to excrete
much waste matter and other deleterious material which may be acting as
a poison in the blood.
Diuretics operate through the kidneys in the same way.
Diaphoretics aid depletion of the blood by pouring water in the form of
sweat from the surface of the skin and stimulating the discharge of
waste material out of its glands, which has the same effect on the blood
pressure.
Antipyretics are remedies to reduce the temperature. This may be
accomplished by depressing the center in the brain that controls heat
production. Some coal-tar products are very effective in this way, but
they have the disadvantage of depressing the heart, which should always
be kept as strong as possible. If they are used it must be with
knowledge of this fact, and it is well to give heart tonics or
stimulants with them. The temperature of the body may be lowered by cold
packs or by showering with cold water. This is a most useful procedure
in many diseases.
Depressants are drugs which act on the heart. They slow or weaken the
action of this organ and reduce the quantity and force of the current of
the blood which is carried to the point of local disease; they lessen
the vitality of the animal, and for this reason are now used much less
than formerly.
Anodynes quiet the nervous system. Pain in the horse, as in the man, is
one of the important factors in the production of fever, and the dulling
of the former often prevents, or at least reduces, the latter. Anodynes
produce sleep, so as to rest the patient and allow recuperation for the
succeeding struggle of the vitality of the animal against the exhausting
drain of the disease.
The diet of an animal suffering from acute inflammation is a factor of
the greatest importance. An overloaded circulation can be starved to a
reduced quantity and to a less rich quality of blood by reducing the
quantity of feed given to the patient. Feeds of easy digestion do not
tire the already fatigued organs of an animal with a torpid digestive
system. Nourishment will be taken by a suffering brute in the form of
slops and cooling drinks when it would be totally refused if offered in
its ordinary form, as hard oats or dry hay, requiring the labor of
grinding between the teeth and swallowing by the weakened muscles of the
jaws and throat.
Tonics and stimulants are remedies which are used to meet special
indications, as in the case of a feeble heart, and which enter into the
after treatment of inflammatory troubles as well as into the acute
stages of them. They brace up weakened and torpid glands; they stimulate
the secretion of the necessary fluids of the body, and hasten the
excretion of the waste material produced by the inflammatory process;
they regulate the action of a weakened heart; they promote healthy
vitality of diseased parts, and aid the chemical changes needed for
returning the altered tissues to their normal condition.
FEVERS.
Fever is a general condition of the animal body in which there is an
elevation of the animal body temperature, which may be only a degree or
two or may be 10 deg. F. The elevation of the body temperature, which
represents tissue change or combustion, is accompanied with an
acceleration of the heart's action, a quickening of the respiration, and
an aberration in the functional activity of the various organs of the
body. These organs may be stimulated to the performance of excessive
work, or they may be incapacitated from carrying out their allotted
tasks, or, in the course of a fever, the two conditions may both exist,
the one succeeding the other. Fever as a disease is usually preceded by
chills as an essential symptom.
Fevers are divided into essential fevers and symptomatic fevers. In
symptomatic fever some local disease, usually of an inflammatory
character, develops first, and the constitutional febrile phenomena are
the result of the primary point of combustion irritating the whole body,
either through the nervous system or directly by means of the waste
material which is carried into the circulation and through the blood
vessels, and is distributed to distal parts. Essential fevers are those
in which there is from the outset a general disturbance of the whole
economy. This may consist of an elementary alteration in the blood or a
general change in the constitution of the tissues. Fevers of the latter
class are usually due to some infecting agent and belong, therefore, to
the class of infectious diseases.
Essential fevers are subdivided into ephemeral fevers, which last but a
short time and terminate by critical phenomena; intermittent fevers, in
which there are alterations of exacerbations of the febrile symptoms and
remissions, in which the body returns to its normal condition or
sometimes to a depressed condition, in which the functions of life are
but badly performed; and continued fevers, which include contagious
diseases, such as glanders, influenza, etc., the septic diseases, such
as pyemia, septicemia, etc., and the eruptive fevers, such as variola,
etc.
Whether the cause of the fever has been an injury to the tissues, such
as a severe bruise, a broken bone, an inflamed lung, or excessive work,
which has surcharged the blood with the waste products of the combustion
of the tissues, which were destroyed to produce force, or the toxins of
influenza in the blood, or the presence of irritating material, either
in the form of living organisms or of their products, as in glanders or
tuberculosis--the general train of symptoms are much the same, varying
as the amount of the irritant differs in quantity, or when some special
quality in them has a specific action on one or another tissue.
There is in fever at first a relaxation of the small blood vessels,
which may have been preceded by a contraction of the same if there was a
chill, and as a consequence there is an acceleration of the current of
the blood. There is, then, an elevation of the peripheral temperature,
followed by a lowering of tension in the arteries and an acceleration in
the movement of the heart. These conditions may be produced by a primary
irritation of the nerve centers of the brain from the effects of heat,
as is seen in thermic fever, or sunstroke, or by the entrance into the
blood stream of disease-producing organisms or their chemical products,
as in anthrax, rinderpest, influenza, etc.
There are times when it is difficult to distinguish between the
existence of fever as a disease and a temporary feverish condition which
is the result of excessive work. Like the condition of congestion of the
lungs, which is normal up to a certain degree in the lungs of a race
horse after a severe race, and morbid when it produces more than
temporary phenomena or when it causes distinct lesions, the temperature
may rise from physiological causes as much as four degrees, so fever,
or, as it is better termed, a feverish condition, may follow any work or
other employment of energy in which excessive tissue change has taken
place; but if the consequences are ephemeral, and no recognizable lesion
is apparent, it is not considered morbid. This condition, however, may
predispose to severe organic disturbance and local inflammations which
will cause disease, as an animal in this condition is liable to take
cold and develop lung fever or a severe enteritis, if chilled or
otherwise exposed.
Fever in all animals is characterized by the same general phenomena, but
we find the intensity of the symptoms modified by the species of animals
affected, by the races which subdivide the species, by the families
which form groups of the races, and by certain conditions in individuals
themselves. For example, a pricked foot in a Thoroughbred may cause
intense fever, while the same injury in the foot of a Clydesdale may
scarcely cause a visible general symptom. In the horse, fever produces
the following symptoms:
The normal body temperature, which varies from 99 deg. to 100 deg. F., is
elevated from 1 deg. to 9 deg.. A temperature of 102 deg. or 103 deg. F. is moderate
fever, 104 deg. to 105 deg. F. is high, and 106 deg. F. and over is excessive. The
temperature is accurately measured by means of a clinical thermometer
inserted in the rectum.
This elevation of temperature can readily be felt by the hand placed in
the mouth of the animal, or in the rectum, and in the cleft between the
hind legs. It is usually appreciable at any point over the surface of
the body and in the expired air emitted from the nostrils. The ears and
cannons are often as hot as the rest of the body, but are sometimes
cold, which denotes a debility in the circulation and irregular
distribution of the blood. The pulse, which in a healthy horse is felt
beating about 42 to 48 times in the minute, is increased to 60, 70, 90,
or even 100. The respirations are increased from 14 or 16 to 24, 30, 36,
or even more. With the commencement of a fever the horse usually has
diminished appetite, or it may have total loss of appetite if the fever
is excessive. There is, however, a vast difference among horses in this
regard. With the same degree of elevation of temperature one horse may
lose its appetite entirely, while another, usually of the more common
sort, will eat at hay throughout the course of the fever, and will even
continue to eat oats or other grains. Thirst is usually increased, but
the animal desires only a small quantity of water at a time, and in most
cases of fever a bucket of water should be kept standing before the
patient, which may be allowed to drink ad libitum. The skin becomes dry
and the hairs stand on end. Sweating is almost unknown in the early
stage of fevers, but frequently occurs later in their course, when an
outbreak of warm sweat is often a most favorable symptom. The mucous
membranes, which are most easily examined in the conjunctivae of the eyes
and inside of the mouth, change color if the fever is an acute one;
without alteration of blood the mucous membranes become of a rosy or
deep-red color at the outset; if the fever is attended with distinct
alteration of the blood, as in influenza, and at the end of two or three
days in severe cases of pneumonia or other extensive inflammatory
troubles the mucous membranes are tinged with yellow, which may even
become a deep ocher in color, the result of the decomposition of the
blood corpuscles and the freeing of their coloring matter, which acts as
a stain. At the outset of a fever the various glands are checked in
their secretions, the salivary glands fail to secrete the saliva, and we
find the surface of the tongue and inside of the cheeks dry and covered
with a brownish, bad-smelling deposit. The excretion from the liver and
intestinal glands is diminished and produces an inactivity of the
digestive organs which causes a constipation. If this is not remedied at
an early period, the undigested material acts as an irritant, and later
we may have it followed by an inflammatory process, producing a severe
diarrhea.
The excretion from the kidneys is sometimes at first entirely
suppressed. It is always considerably diminished, and what urine is
passed is dark in color, undergoes ammoniacal change rapidly, and
deposits quantities of salts. At a later period the diminished excretion
may be replaced by an excessive excretion, which aids in carrying off
waste products and usually indicates an amelioration of the fever.
While the ears, cannons, and hoofs of a horse suffering from fever are
usually found hot, they may frequently alternate from hot to cold, or be
much cooler than they normally are. This latter condition usually
indicates great weakness on the part of the circulatory system.
It is of the greatest importance, as an aid in diagnosing the gravity of
an attack of fever and as an indication in the selection of its mode of
treatment, to recognize the exact cause of a febrile condition in the
horse. In certain cases, in very nervous animals, in which fever is the
result of nerve influence, a simple anodyne, or even only quiet with
continued care and nursing, will sometimes be sufficient to diminish it.
When fever is the result of local injury, the cure of the cause produces
a cessation in the constitutional symptoms. When it is the result of a
pneumonia or other severe parenchymatous inflammation, it usually lasts
for a definite time, and subsides with the first improvement of the
local trouble, but in these cases we constantly have exacerbations of
fever due to secondary inflammatory processes, such as the formation of
small abscesses, the development of secondary bronchitis, or the death
of a limited quantity of tissue (gangrene).
In specific cases, such as influenza, strangles, and septicemia, there
is a definite poison in the blood-vessel system and carried to the heart
and to the nervous system, which produces a peculiar irritation, usually
lasting for a specific period, during which the temperature can be but
slightly diminished by any remedy.
In cases attended with complications, the diagnosis at times becomes
still more difficult, as at the end of a case of influenza which becomes
complicated with pneumonia. The high temperature of the simple
inflammatory disease may be grafted on that of the specific trouble, and
the determination of the cause of the fever, as between the two, is
therefore frequently a difficult matter but an important one, as upon it
depends the mode of treatment.
Any animal suffering from fever, whatever the cause, is much more
susceptible to attacks of local inflammation, which become complications
of the original disease, than are animals in sound health. In fever we
have the tissues and the walls of the blood vessels weakened, we have an
increased current of more or less altered blood flowing through the
vessels and stagnating in the capillaries, which need but an exciting
cause to transform the passive congestion of fever into an active
congestion and acute inflammation. These conditions become still more
distinct when the fever is accompanied with a decided deterioration in
the blood itself, as is seen in influenza, septicemia, and at the
termination of severe pneumonias.
Fever, with its symptoms of increased temperature, acceleration of the
pulse, acceleration of respiration, dry skin, diminished secretions,
etc., must be considered as an indication of organic disturbance. This
organic disturbance may be the result of local inflammation or other
irritants acting through the nerves on nerve centers, alterations of the
blood, in which a poison is carried to the nerve centers, or direct
irritants to the nerve centers themselves, as in cases of heat stroke,
injury to the brain, etc.
The treatment of fever depends upon its cause. One of the important
factors in treatment is absolute quiet. This may be obtained by placing
a sick horse in a box stall, away from other animals and extraneous
noises and sheltered from excessive light and drafts of air. Anodynes,
belladonna, hyoscyamus, and opium act as antipyretics simply by quieting
the nervous system. As an irritant exists in the blood in most cases of
fever, any remedy which will favor the excretion of foreign elements
from it will diminish this cause. We therefore use diaphoretics to
stimulate the sweat and excretions from the skin; diuretics to favor the
elimination of matter by the kidneys; cholagogues and laxatives to
increase the action of the liver and intestines, and to drain from these
important organs all the waste material which is aiding to choke up and
congest their rich plexuses of blood vessels. The heart becomes
stimulated to increased action at the outset of a fever, but this does
not indicate increased strength; on the contrary, it indicates the
action of an irritant to the heart that will soon weaken it. It is,
therefore, irrational further to depress the heart by the use of such
drugs as aconite. It is better to strengthen it and to favor the
elimination of the substance that is irritating it. The increased blood
pressure throughout the body may be diminished by lessening the quantity
of blood. This is obtained in some cases with advantage when the disease
is but starting and the animal is plethoric by direct abstraction of
blood, as in bleeding from the jugular or other veins; or by
derivatives, such as mustard, turpentine, or blisters applied to the
skin; or by setons, which draw to the surface the fluid of the blood,
thereby lessening its volume without having the disadvantage of
impoverishing the elements of the blood found in bleeding. In many cases
antipyretics given by the mouth and cold applied to the skin are most
useful.
When the irritation which is the cause of fever is a specific one,
either in the form of bacteria (living organisms), as in glanders,
tuberculosis, influenza, septicemia, etc., or in the form of a foreign
element, as in rheumatism, gout, hemaglobinuria, and other so-called
diseases of nutrition, we employ remedies which have been found to have
a direct specific action on them. Among the specific remedies for
various diseases are counted quinin, carbolic acid, salicylic acid,
antipyrene, mercury, iodin, the empyreumatic oils, tars, resins,
aromatics, sulphur, and a host of other drugs, some of which are of
known effect and others of which are theoretical in action. Certain
remedies, like simple aromatic teas, vegetable acids, such as vinegar,
lemon juice, etc., alkalines in the form of salts, sweet spirits of
niter, etc., which are household remedies, are always useful, because
they act on the excreting organs and ameliorate the effects of fever.
Other remedies, which are to be used to influence the cause of fever,
must be selected with judgment and from a thorough knowledge of the
nature of the disease.
METHODS OF ADMINISTERING MEDICINES.
By CH. B. MICHENER, V. S.
[Revised by Leonard Pearson, B. S., V. M. D.]
Medicine may enter the body through any of the following designated
channels: First, by the mouth; second, by the air passages; third, by
the skin; fourth, by the tissue beneath the skin (hypodermic methods);
fifth, by the rectum; sixth, by the genito-urinary passages; and,
seventh, by the blood (intravenous injections).
BY THE MOUTH.--Medicines can be given by the mouth in the form of
solids, as powders or pills; liquids, and pastes, or electuaries.
_Powders._--Solids administered as powders should be as finely
pulverized as possible, in order to obtain rapid solution and
absorption. Their action is in this way facilitated and intensified.
Powders must be free from any irritant or caustic action upon the mouth.
Those that are without any disagreeable taste or smell are readily eaten
with the feed or taken in the drinking water. When placed with the feed
they should first be dissolved or suspended in water and thus sprinkled
on the feed. If mixed dry the horse will often leave the medicine in the
bottom of his manger. Nonirritant powders may be given in capsules, as
balls are given.
_Pills, or "balls"_ when properly made, are cylindrical in shape, 2
inches in length and about three-fourths of an inch in diameter. They
should be fresh, but if necessary to keep them some time they should be
made up with glycerin, or some such agent, to prevent their becoming too
hard. Very old, hard balls are sometimes passed whole with the manure
without being acted upon at all. Paper is sometimes wrapped around balls
when given, if they are so sticky as to adhere to the fingers or the
balling gun. Paper used for this purpose should be thin but firm, as the
tougher tissue papers. Balls are preferred to drenches when the medicine
is extremely disagreeable or nauseating; when the dose is not too large;
when the horse is difficult to drench; or when the medicine is intended
to act slowly. Certain medicines can not or should not be made into
balls, as medicines requiring to be given in large doses, oils, caustic
substances, unless in small dose and diluted and thoroughly mixed with
the vehicle, deliquescent, or efflorescent salts. Substances suitable
for balls can be made up by the addition of honey, sirup, soap, etc.,
when required for immediate use. Gelatin capsules of different sizes are
now obtainable and are a convenient means of giving medicines in ball
form.
When balls are to be given we should observe the following directions:
In shape they should be cylindrical, of the size above mentioned, and
soft enough to be easily compressed by the fingers. If made round or
egg-shaped, if too long or too hard, they are liable to become fixed in
the gullet and cause choking. Balls may be given with the "balling gun"
(obtainable at any veterinary instrument maker's) or by the hand. If
given by the hand a mouth speculum or gag may be used to prevent the
animal from biting the hand or crushing the ball. Always loosen the
horse before attempting to give a ball; if tied he may break his halter
and injure himself or the one giving the ball. With a little practice it
is much easier to give a ball without the mouth gag, as the horse always
fights more or less against having his mouth forced open. The tongue
must be firmly grasped with the left hand and gently pulled forward; the
ball, slightly moistened, is then to be placed with the tips of the
fingers of the right hand as far back into the mouth as possible; as the
tongue is loosened it is drawn back into the mouth and carries the ball
backward with it. The mouth should be kept closed for a minute or two.
We should always have a pail of water at hand to offer the horse after
balling. This precaution will often prevent him from coughing out the
ball or its becoming lodged in the gullet.
_Pastes or electuaries_ are medicines mixed with licorice-root powder,
ground flaxseed, molasses, or sirup to the consistency of honey, or a
"soft solid." They are intended, chiefly, to act locally upon the mouth
and throat. They are given by being spread upon the tongue, gums, or
teeth with a wooden paddle or strong, long-handled spoon.
_Liquids._--It is, very often, impossible to get balls properly made, or
to induce owners or attendants to attempt to give them, and for these
reasons medicines by the mouth are mostly given in the form of liquids.
Liquids may be given as drenches when the dose is large, or they may,
when but a small quantity is administered, be injected into the mouth
with a hard-rubber syringe or be poured upon the tongue from a small
vial.
When medicine is to be given as a drench we must be careful to use water
or oil enough to dissolve or dilute it thoroughly; more than this Wakes
the drench bulky and is unnecessary. Insoluble medicines, if not
irritant or corrosive, may be given simply suspended in water, the
bottle to be well shaken immediately before giving the drench. The
bottle used for drenching purposes should be clean, strong, and smooth
about its neck; it should be without shoulders, tapering, and of a size
to suit the amount to be given. A horn or tin bottle may be better,
because it is not so easily broken by the teeth. If the dose is a small
one the horse's head may be held up by the left hand, while the medicine
is poured into the mouth by the right. The left thumb is to be placed in
the angle of the lower jaw, and the fingers spread out in such manner
as to support the lower lip. Should the dose be large, the horse ugly,
or the attendant unable to support the head as directed above, the head
is then to be held up by running the tines of a long-handled wooden fork
under the noseband of the halter or the halter strap or a rope may be
fastened to the noseband and thrown over a limb, beam, or through a
pulley suspended from the ceiling. Another way of supporting the head is
to place a loop in the end of a rope, and introduce this loop into the
mouth just behind the upper front teeth or tusks of the upper jaw, the
free end to be run through a pulley, as before described, and held by an
assistant. It is never to be fastened, as the horse might in that case
do himself serious injury. The head is to be elevated just enough to
prevent the horse from throwing the liquid out of his mouth. The line of
the face should be horizontal, or only the least bit higher. If the head
is drawn too high the animal can not swallow with ease or even with
safety. (If this is doubted, just fill your mouth with water, throw-back
the head as far as possible, and then try to swallow.) The person giving
the drench should stand on some object in order to reach the horse's
mouth--on a level, or a little above it. The bottle or horn is then to
be introduced at the side of the mouth, in front of the molar teeth, in
an upward direction. This will cause the horse to open his mouth, when
the base of the bottle is to be elevated, and about 4 ounces of the
liquid allowed to escape on the tongue as far back as possible, care
being taken not to get the neck of the bottle between the back teeth.
The bottle is to be immediately removed, and if the horse does not
swallow this can be encouraged by rubbing the fingers or neck of the
bottle against the roof of the mouth, occasionally removing them. As
soon as this is swallowed repeat the operation until he has taken all
the drench. If coughing occurs, or if, by any mishap, the bottle should
be crushed in the mouth, lower the head immediately.
Do not rub, pinch, or pound the throat nor draw out the tongue when
giving a drench. These processes in no way aid the horse to swallow and
oftener do harm than good. In drenching, swallowing may be hastened by
pouring into the nose of the horse, while the head is high, a few
teaspoonfuls of clean water, but _drenches must never be given through
the nose_. Large quantities of medicine given by pouring into the nose
are liable to strangle the animal, or, if the medicine is irritating, it
sets up an inflammation of the nose, fauces, windpipe, and sometimes the
lungs.
BY THE AIR PASSAGES.--Medicines are administered to the lungs and upper
air passages by insufflation, inhalation, injection, and nasal douche.
_Insufflation_ consists in blowing an impalpable powder directly into
the nose. It is but rarely resorted to.
_Inhalation._--Gaseous and volatile medicines are given by inhalation,
as is also medicated steam or vapor. Of the gases used there may be
mentioned, as the chief ones, sulphurous acid gas and, occasionally,
chlorin. The animal or animals are to be placed in a tight room, where
these gases are generated until the atmosphere is sufficiently
impregnated with them. Volatile medicines--as the anesthetics (ether,
chloroform, etc.)--are to be given by the attending surgeon only.
Medicated vapors are to be inhaled by placing a bucket containing hot
water, vinegar and water, scalded hay or bran, to which carbolic acid,
iodin, compound tincture of benzoin, or other medicines have been added,
in the bottom of a long grain bag. The horse's nose is to be inserted
into the top of the bag, and he thus inhales the "medicated steam." Care
must be taken not to have it hot enough to scald the animal. The vapor
from scalding bran or hay is often thus inhaled to favor discharges in
sore throat or "distemper."
_Injections_ are made into the trachea by means of a hypodermic syringe.
This method of medication is used for the purpose of treating local
diseases of the trachea and upper bronchial tubes. It has also been used
as a mode of administering remedies for their constitutional effect, but
is now rarely used for this purpose.
_The nasal douche_ is employed by the veterinarian in treating some
local diseases of the nasal chambers. Special appliances and
professional knowledge are necessary when using liquid medicines by this
method. It is not often resorted to, even by veterinary surgeons, since,
as a rule, the horse objects very strongly to this mode of medication.
BY THE SKIN.--Medicines are often administered to our hair-covered
animals by the skin, yet care must be taken in applying some
medicines--as tobacco water, carbolic-acid solutions, strong creolin
solutions, mercurial ointment, etc.--over the entire body, as poisoning
and death follow in some instances from absorption through the skin. For
the same reasons care must also be exercised and poisonous medicines not
applied over very large raw or abraded surfaces. With domestic animals
medicines are only to be applied by the skin to allay local pain or cure
local disease.
BY THE TISSUE BENEATH THE SKIN (HYPODERMATIC METHOD).--Medicines are
frequently given by the hypodermic syringe under the skin. It is not
safe for any but medical or veterinary practitioners to use this form of
medication, since the medicines thus given are powerful poisons. There
are many precautions to be observed, and a knowledge of anatomy is
indispensable. One of the chief precautions has to do with the
sterilization of the syringe. If it is not sterile an abscess may be
produced.
BY THE RECTUM.--Medicines may be given by the rectum when they can not
be given by the mouth, or when they are not retained in the stomach;
when we want a local action on the last gut; when it is desired to
destroy the small worms infesting the large bowels or to stimulate the
peristaltic motion of the intestines and cause evacuation. Medicines are
in such cases given in the form of suppositories or as liquid injections
(enemas.) Foods may also be given in this way.
_Suppositories_ are conical bodies made up of oil of theobroma and opium
(or whatever medicine is indicated in special cases), and are introduced
into the rectum or vagina to allay irritation and pain of these parts.
They are not much used in treating horses.
_Enemas_, when given for absorption, should be small in quantity,
neutral or slightly acid in reaction, and of a temperature of from 90 deg.
to 100 deg. F. These, like feeds given by the rectum, should be introduced
only after the last bowel has been emptied by the hand or by copious
injections of tepid water. Enemas, or clysters, if to aid the action of
physics, should be in quantities sufficient to distend the bowel and
cause the animal to eject them. Simple water, salt and water, or soap
and water, in quantities of a gallon or more, may be given every half
hour. It is best that the horse retain them for some little time, as the
liquid serves to moisten the dung and favors a passage. Stimulating
enemas, as glycerin, should be administered after those already
mentioned have emptied the last bowel, with the purpose of still further
increasing the natural motion of the intestines and aiding the purging
medicine.
Liquids may be thrown into the rectum by the means of a large syringe or
a pump. A very good "irrigator" can be bought of any tinsmith at a
trifling cost, and should be constantly at hand on every stock farm. It
consists of a funnel about 6 inches deep and 7 inches in diameter, which
is to be furnished with a prolongation to which a piece of rubber hose,
such as small garden hose, 4 feet long may be attached. The hose, well
oiled, is to be inserted gently into the rectum about 2 feet. The liquid
to be injected may then be poured in the funnel and the pressure of the
atmosphere will force it into the bowels. This appliance is better than
the more complicated and expensive ones.
Ordinary cold water or even ice-cold water is highly recommended by many
as a rectal injection for horses overcome by the excessive heat of
summer, and may be given by this simple pipe.
BY THE GENITO-URINARY PASSAGES.--This method of medication is especially
useful in treating local diseases of the genito-urinary organs. It finds
its chief application in the injection and cleansing of the uterus and
vagina. For this purpose a large syringe or the irrigator described
above may be used.
BY THE BLOOD.--Injections directly into veins are to be practiced by
medical or veterinary practitioners only, as are probably some other
means of giving medicines--intratracheal injections, etc.
[Illustration: PLATE III.
DIGESTIVE APPARATUS.
1. Mouth. 2. Pharynx. 3. Esophagus. 4. Diaphragm. 5. Spleen. 6. Stomach.
7. Duodenum. 8. Liver, upper extremity. 9. Large colon. 10. Cecum. 11.
Small intestine. 12. Floating colon. 13. Rectum. 14. Anus. 15. Left
kidney and its ureter. 16. Bladder. 17. Urethra.]
DISEASES OF THE DIGESTIVE ORGANS.
By CH. B. MICHENER, V. S.
[Revised by John R. Mohler, V. M. D.]
It is not an easy task to write "a plain account of the common diseases,
with directions for preventive measures, hygienic care, and the simpler
forms of medical treatment," of the digestive organs of the horse. Being
limited as to space, the endeavor has been made to give simply an
outline--to state the most important facts--leaving many gaps, and
continually checking the disposition to write anything like a full
description as to cause, prevention, and modes of treatment of diseases.
WATER.
It is generally held, at least in practice, that any water that stock
can be induced to drink is sufficiently pure for their use. This
practice occasions losses that would startle us if statistics were at
hand. Water that is impure from the presence of decomposing organic
matter, such as is found in wells and ponds in close proximity to manure
heaps and cesspools, is frequently the cause of diarrhea, dysentery, and
many other diseases of stock, while water that is impregnated with
different poisons and contaminated in very many instances with specific
media of contagion produces death.
Considering first the quantity of water required by the horse, it may be
stated that when our animals have access to water continually they never
drink to excess. Were the horse subjected to ship voyages or any other
circumstances where he must depend upon his attendant for the supply of
water, it may be roughly stated that he requires a daily average of
about 8 gallons of water. This varies somewhat upon the character of his
feed; if upon green feed, less water will be needed than when fed upon
dry hay and grain.
The time of giving water should be carefully studied. At rest, the horse
should receive it at least three times a day; when at work, more
frequently. The rule should be to give it in small quantities and often.
There is a popular fallacy that if a horse is warm he should not be
allowed to drink, many asserting that the first swallow of water
"founders" the animal or produces colic. This is erroneous. No matter
how warm a horse may be, it is always entirely safe to allow him from
six to ten swallows of water. If this is given on going into the
stable, he should have at once a pound or two of hay and allowed to rest
about an hour before feeding. If water is now offered him it will in
many cases be refused, or at least he will drink but sparingly. The
danger, then, is not in the "first swallow" of water, but is due to the
excessive quantity that the animal will take when warm if he is not
restrained.
Ice-cold water should never be given to horses. It may not be necessary
to add hot water, but we should be careful in placing water troughs
about our barns to have them in such position that the sun may shine
upon the water during the winter mornings. Water, even though it is thus
cold, seldom produces serious trouble if the horse has not been deprived
for a too great length of time.
In reference to the purity of water, Smith, in his "Veterinary Hygiene,"
classes spring water, deep-well water, and upland surface water as
wholesome; stored rain water and surface water from cultivated land as
suspicious; river water to which sewage gains access and shallow-well
water as dangerous. The water that is used so largely for drinking
purposes for stock throughout some States can not but be impure. I refer
to those sections where there is an impervious clay subsoil. It is the
custom to scoop, or hollow out, a large basin in the pastures. During
rains these basins become filled with water. The clay subsoil, being
almost impervious, acts as a jug, and there is no escape for the water
except by evaporation. Such water is stagnant, but would be kept
comparatively fresh by subsequent rains were it not for the fact that
much organic matter is carried into it by surface drainage during each
succeeding storm. This organic matter soon undergoes decomposition, and,
as the result, we find diseases of different kinds much more prevalent
where this water is drunk than where the water supply is wholesome.
Again, it must not be lost sight of that stagnant surface water is much
more certainly contaminated than is running water by one diseased animal
of the herd, thus endangering the remainder.
The chief impurities of water may be classified as organic and
inorganic. The organic impurities are either animal or vegetable
substances. The salts of the metals are the inorganic impurities. Lime
causes hardness of water, and occasion will be taken to speak of this
when describing intestinal concretions. Salts of lead, iron, and copper
are also frequently found in water; they also will be referred to.
About the only examination of water that can be made by the average
stock raiser is to observe its taste, color, smell, and clearness. Pure
water is clear and is without taste or smell.
Chemical and microscopic examination will frequently be necessary in
order to detect the presence of certain poisons, bacteria, etc., and
can, of course, be conducted by experts only.
FEEDS AND FEEDING.
In this place one can not attempt anything like a comprehensive
discussion of the subject of feeds and feeding, and I must content
myself with merely giving a few facts as to the different kinds of feed,
preparation, digestibility, proper time of feeding, quality, and
quantity. Improper feeding and watering will doubtless account for more
than one-half the digestive disorders met with in the horse, and hence
the reader can not fail to see how very important it is to have some
proper ideas concerning these subjects.
KINDS OF FEED.
In this country horses are fed chiefly upon hay, grass, corn fodder,
roots, oats, corn, wheat, and rye. Many think that they could be fed on
nothing else. Stewart, in "The Stable Book," gives the following extract
from Loudon's Encyclopedia of Agriculture, which is of interest at this
point:
In some sterile countries they [horses] are forced to subsist
on dried fish, and even on vegetable mold; in Arabia, on milk,
flesh balls, eggs, broth. In India horses are variously fed.
The native grasses are judged very nutritious. Few, perhaps no,
oats are grown; barley is rare, and not commonly given to
horses. In Bengal a vetch, something like the tare, is used. On
the western side of India a sort of pigeon pea, called gram
(_Cicer arietinum_), forms the ordinary food, with grass while
in season, and hay all the year round. Indian corn or rice is
seldom given. In the West Indies maize, guinea corn, sugar-corn
tops, and sometimes molasses are given. In the Mahratta country
salt, pepper, and other spices are made into balls, with flour
and butter, and these are supposed to produce animation and to
fine the coat. Broth made from sheep's head is sometimes given.
In France, Spain, and Italy, besides the grasses, the leaves of
limes, vines, the tops of acacia, and the seeds of the carob
tree are given to horses.
We can not, however, leave aside entirely here a consideration of the
digestibility of feeds; and by this we mean the readiness with which
they undergo those changes in the digestive canal that fit them for
absorption and deposition as integral parts of the animal economy.
The age and health of the animal will, of course, modify the
digestibility of feeds, as will also the manner and time of harvesting,
preserving, and preparing.
In the horse digestion takes place principally in the intestines, and
here, as in all other animals and with all feeds, it is found that a
certain part only of the provender is digested; another portion is
undigested. This proportion of digested and undigested feed must claim
passing notice at least, for if the horse receives too much feed, or
bulky feed containing much indigestible waste, a large portion of it
must pass out unused, entailing not only the loss of this unused feed,
but also calling for an unnecessary expenditure of vital force on the
part of the digestive organs of the horse. It is thus that, in fact, too
much feed may make an animal poor.
In selecting feed for the horse we should remember the anatomical
arrangement of the digestive organs, as well as the physiological
functions performed by each one of them. Feeds must be wholesome, clean,
and sweet, the hours of feeding regular, the mode of preparation found
by practical experience to be the best must be adhered to, and
cleanliness in preparation and administration must be observed.
The length of time occupied by stomach digestion in the horse varies
with the different feeds. Hay and straw pass out of the stomach more
rapidly than oats. It would seem to follow, then, that oats should be
given after hay, for if reversed the hay would cause the oats to be sent
onward into the intestines before being fully acted upon by the stomach,
and as a result produce indigestion. Experience confirms this. There is
another good reason why hay should be given first, particularly if the
horse is very hungry or if exhausted from overwork, namely, it requires
more time in mastication (insuring proper admixture of saliva) and can
not be bolted, as are the grains. In either instance water must not be
given soon after feeding, as it washes or sluices the feed from the
stomach before it is fitted for intestinal digestion.
The stomach begins to empty itself very soon after the commencement of
feeding, and continues rapidly while eating. Afterwards the passage is
slower, and several hours are required before the stomach is entirely
empty. The nature of the work required of the horse must guide us in the
selection of his feed. Rapid or severe labor can not be performed on a
full stomach. For such labor feed must be given in small quantity and
about two hours before going to work. Even horses intended for slow work
must never be engorged with bulky, innutritious feed immediately before
going to labor. The small stomach of the horse would seem to lead us to
the conclusion that he should be fed in small quantities and often,
which, in reality, should be done. The disproportion between the size of
the stomach and the quantity of water drunk tells us plainly that the
horse should always be watered before feeding. One of the common errors
of feeding, and the one that produces more digestive disorders than any
other, is _to feed too soon after a hard day's work_. This must never be
done. If a horse is completely jaded, it will be found beneficial to
give him an alcoholic stimulant on going into the stable. A small
quantity of hay may then be given, but his grain should be withheld for
one or two hours. These same remarks will apply with equal force to the
horse that for any reason has been fasting for a long time. After a
fast, feed less than the horse would eat, for if allowed too much the
stomach becomes engorged, its walls paralyzed, and "colic" is almost
sure to follow. The horse should be fed three or four times a day. It
will not do to feed him entirely upon concentrated feed. Bulky feed must
be given to detain the grains in their passage through the intestinal
tract; bulk also favors distention, and thus mechanically aids
absorption. For horses that do slow work the greater part of the time,
chopped or cut hay fed with crushed oats, ground corn, etc., is the best
manner of feeding, as it gives the required bulk, saves time, and half
the labor of feeding.
Sudden changes of diet are always dangerous. When desirous of changing,
do so very gradually. If a horse is accustomed to oats, a sudden change
to a full meal of corn will almost always sicken him. If we merely
intend to increase the quantity of the _usual_ feed, this also must be
done gradually. The quantity of feed given must always be in proportion
to the amount of labor to be performed. If a horse is to do a small
amount of work, or rest entirely from work for a few days, he should
receive a proportionate quantity of feed. If this should be observed
even on Saturday night and Sunday, there would be fewer cases of "Monday
morning sickness," such as colics and lymphangitis.
Feeds should also be of a more laxative nature when the horse is to
stand for several days.
MUSTY OR MOLDY FEEDS.--Above all things, avoid feeding musty or moldy
feeds. They are very frequent causes of disease of different kinds. Lung
trouble, such as bronchitis and "heaves," often follows their use. The
digestive organs always suffer from moldy or musty feeds. Musty hay is
generally considered to produce disorder of the kidneys, and all know of
the danger from feeding pregnant animals upon ergotized grasses or
grains. It has often been said to produce that peculiar disease known
variously as cerebrospinal meningitis, putrid sore throat, or choking
distemper.
HAY.--The best hay for horses is timothy. It should be about one year
old, of a greenish color, crisp, clean, fresh, and possessing a sweet,
pleasant aroma. Even this good hay, if kept too long, loses part of its
nourishment, and, while it may not be positively injurious, it is hard,
dry, and indigestible. New hay is difficult to digest, produces much
salivation (slobbering), and occasional purging and irritation of the
skin. If fed at all it should be mixed with old hay.
_Second crop, or aftermath._--This is not considered good hay for
horses, but it is prized by some farmers as good for milch cows, the
claim being made that it increases the flow of milk. The value of hay
depends upon the time of cutting, as well as care in the curing. Hay
should be cut when in full flower, but before the seeds fall; if left
longer it becomes dry, woody, and lacks in nutrition. An essential
point in making hay is that when the crop is cut it should remain in the
field as short a time as possible. If left too long in the sun it loses
color, flavor, and dries or wastes. Smith asserts that one hour more
than is necessary in the sun causes a loss of 15 to 20 per cent in the
feeding value of hay. It is impossible to state any fixed time that hay
must have to cure, this depending, of course, upon the weather,
thickness of the crop, and many other circumstances; but it is well
known that in order to preserve the color and aroma of hay it should be
turned or tedded frequently and cured as quickly as possible. On the
other hand, hay spoils in the mow if harvested too green or when not
sufficiently dried. Mow-burnt hay produces disorder of the kidneys and
bowels and causes the horse to fall off in condition.
The average horse on grain should be allowed from 10 to 12 pounds of
good hay a day. It is a mistake of many to think that horses at light
work can be kept entirely on hay. Such horses soon become potbellied,
fall off in flesh, and do not thrive. The same is true of colts; unless
the latter are fed with some grain they grow up to be long, lean, gawky
creatures, and never make so good horses as those accustomed to grain
with, or in addition to, their hay.
STRAW.--The straws are not extensively fed in this country, and when
used at all they should be cut and mixed with hay and ground or crushed
grain. Wheat, rye, and oat straw are the ones most used; of these, oat
straw is most easily digested and contains the most nourishment. Pea and
bean straw are occasionally fed to horses, the pea being preferable,
according to most writers.
CHAFF.--Wheat and rye chaff should never be used as a feed for horses.
The beards frequently become lodged in the mouth or throat and are
productive of more or less serious trouble. In the stomach and
intestines they often serve as the nucleus of the "soft concretions,"
which are to be described when treating of obstructions of the digestive
tract.
Oat chaff, if fed in small quantities and mixed with cut hay or corn
fodder, is very much relished by horses. It is not to be given in large
quantities, as I have repeatedly witnessed a troublesome and sometimes
fatal diarrhea following the practice of allowing horses or cattle free
access to a pile of oat chaff.
GRAINS.--Oats take precedence of all grains as a feed for horses, as the
ingredients necessary for the complete nutrition of the body exist in
them in the best proportions. Oats are, besides, more easily digested
and a larger proportion absorbed and converted into the various tissues
of the body. Care must be taken in selecting oats. According to Stewart,
the best oats are one year old, plump, short, hard, clean, bright, and
sweet. New oats are indigestible. Kiln-dried oats are to be refused, as
a rule, for even though originally good this drying process injures
them. Oats that have sprouted or fermented are injurious and should
never be fed. Oats are to be given either whole or crushed--whole in the
majority of instances; crushed to old horses and those having defective
teeth. Horses that bolt their feed are also best fed upon crushed oats
and out of a manger large enough to permit of spreading the grain in a
thin layer.
In addition to the allowance of hay above mentioned, the average horse
requires about 12 quarts of good oats daily. The best oats are those cut
about one week before they are fully ripe. Not only is the grain richer
in nutritive materials at this time, but there is also less waste from
"scattering" than if left to become dead ripe. Moldy oats, like hay and
straw, not only produce serious digestive disorders but have been the
undoubted cause of outbreaks of that dread disease in horses, already
referred to, characterized by inability to eat or drink, sudden
paralysis, and death.
WHEAT AND RYE.--These grains are not to be used for horses except in
small quantities, bruised or crushed, and fed mixed with other grains or
hay. If fed alone, in any considerable quantities, they are almost
certain to produce digestive disorders, laminitis (founder), and similar
troubles. They should never constitute more than one-fourth the grain
allowance, and should always be ground or crushed.
BRAN.--The bran of wheat is the one most used, and its value as a
feeding stuff is variously estimated. It is not to be depended upon if
given alone, but may be fed with other grains. It serves to keep the
bowels open. Sour bran is not to be given, for it disorders the stomach
and intestines and may even produce serious results.
MAIZE (CORN).--This grain is not suitable as an exclusive feed for young
horses, as it is deficient in salts. It is fed whole or ground. Corn on
the cob is commonly used for horses affected with "lampas." If the corn
is old and is to be fed in this manner it should be soaked in pure,
clean water for 10 or 12 hours. Corn is better given ground, and fed in
quantities of from 1 to 2 quarts at a meal, mixed with crushed oats or
wheat bran. Great care should be taken in giving corn to a horse that is
not accustomed to its use. It must be commenced in small quantities and
very gradually increased. I know of no grain more liable to produce what
is called acute indigestion than corn if these directions are not
observed.
LINSEED.--Ground linseed is occasionally fed with other feeds to keep
the bowels open and to improve the condition of the skin. It is of
particular service during convalescence, when the bowels are sluggish in
their action. Linseed tea is very often given in irritable or inflamed
conditions of the digestive organs.
POTATOES.--These are used as an article of feed for the horse in many
sections. If fed raw and in large quantities they often produce
indigestion. Their digestibility is increased by steaming or boiling.
They possess, in common with other roots, slight laxative properties.
BEETS.--These are not much used as feed for horses.
CARROTS.--These make a most excellent feed, particularly during
sickness. They improve the appetite and slightly increase the action of
the bowels and kidneys. They possess also certain alterative properties,
making the coat smooth and glossy. Some veterinary writers assert that
chronic cough is cured by giving carrots for some time. The roots may be
considered, then, as an adjunct to the regular regimen, and if fed in
small quantities are highly beneficial.
GRASSES.--Grass is the natural food of horses. It is composed of a great
variety of plants, differing widely as to the amount of nourishment
contained, some being almost entirely without value and only eaten when
nothing else is obtainable, while others are positively injurious, or
even poisonous. None of the grasses are sufficient to keep the horse in
condition for work. Horses thus fed are "soft," sweat easily, purge, and
soon tire on the road or when at hard work. Grass is indispensable to
growing stock, and there is little or no doubt that it acts as an
alterative when given to horses accustomed to grain and hay. It must be
given to such horses in small quantities at first. The stomach and
intestines undergo rest, and recuperate if the horse is turned to grass
for a time each year. It is also certain that during febrile diseases
grass acts almost as a medicine, lessening the fever and favoring
recovery. Wounds heal more rapidly than when the horse is on grain, and
some chronic disorders (chronic cough, for instance) disappear entirely
when at grass. In my experience, grass does more good when the horse
crops it himself. This may be due to the sense of freedom he enjoys at
pasture, to the rest to his feet and limbs, and for many other similar
reasons. When cut for him it should be fed fresh or when but slightly
wilted.
SILAGE.--Regarding silage as a feed for horses, Rommel in Farmers'
Bulletin 578 writes as follows:
Silage has not been generally fed to horses, partly on account
of a certain amount of danger which attends its use for this
purpose, but still more, perhaps, on account of prejudice. In
many cases horses have been killed by eating moldy silage, and
the careless person who fed it at once blamed the silage
itself, rather than his own carelessness and the mold which
really was the cause of the trouble. Horses are peculiarly
susceptible to the effects of molds, and under certain
conditions certain molds grow on silage which are deadly
poisons to both horses and mules. Molds must have air to grow,
and therefore silage which is packed air-tight and fed out
rapidly will not become moldy. If the feeder watches the silage
carefully as the weather warms up he can soon detect the
presence of mold. When mold appears, feeding to horses or mules
should stop immediately.
It is also unsafe to feed horses frozen silage on account of
the danger of colic. * * *
To summarize, silage is safe to feed to horses and mules only
when it is made from fairly mature corn, properly stored in the
silo. When it is properly stored and is not allowed to mold, no
feed exceeds it as a cheap winter ration. It is most valuable
for horses and mules which are not at heavy work, such as brood
mares and work horses during the slack season. With plenty of
grain on the cornstalks, horses will keep in good condition on
a ration of 20 pounds of silage and 10 pounds of hay for each
1,000 pounds of live weight.
PREPARATION OF FEEDS.
Feed is prepared for any of the following reasons: To render it more
easily eaten; to make it more digestible; to economize in amount; to
give it some new property; and to preserve it. We have already spoken of
the preparation of drying, and need not revert to this again, as it only
serves to preserve the different feeds. Drying does, however, change
some of the properties of feed, _i. e._, removes the laxative tendency
of most of them.
The different grains are more easily eaten when ground, crushed, or even
boiled. Rye or wheat should never be given whole, and even of corn it is
found that there is less waste when ground, and, in common with all
other grains, it is more easily digested than when fed whole.
Hay and fodder are economized when cut in short pieces. Not only will
the horse eat the necessary quantity in a shorter time, but it will be
found that there is less waste, and the mastication of the grains (whole
or crushed) fed with them is insured.
Reference has already been made to those horses that bolt their feed,
and we need only remark here that the consequences of such ravenous
eating may be prevented if the grains are fed with cut hay, straw, or
fodder. Long or uncut hay should also be fed, even though a certain
quantity of hay or straw is cut and fed mixed with grain.
One objection to feeding cut hay mixed with ground or crushed grains,
and wetted, must not be overlooked during the hot months. Such feed is
liable to undergo fermentation if not fed directly after it is mixed;
even the mixing trough, unless frequently scalded and cleaned, becomes
sour and enough of its scrapings are given with the feed to produce
flatulent (wind) colic. A small quantity of salt should always be mixed
with such feed. Bad hay should never be cut simply because it insures a
greater consumption of it; bad feeds are dear at any price, and should
never be fed.
The advantage of boiling roots has been mentioned. Not only does this
render them less liable to produce digestive disorders, but it also
makes them clean. Boiling or steaming grains is to be recommended when
the teeth are poor, or when the digestive organs are weak.
DISEASES OF THE TEETH.
_Dentition._--This covers the period during which the young horse is
cutting his teeth--from birth to the age of 5 years. With the horse more
difficulty is experienced in cutting the second or permanent teeth than
with the first or milk teeth. There is a tendency among farmers and many
veterinarians to pay too little attention to the teeth of young horses.
Percivall relates an instance illustrative of this that is best told in
his own words:
I was requested to give my opinion concerning a horse, then in
his fifth year, who had fed so sparingly for the last
fortnight, and so rapidly declined in condition in consequence,
that his owner, a veterinary surgeon, was under no light
apprehensions about his life. He had himself examined his mouth
without having discovered any defect or disease, though another
veterinary surgeon was of opinion that the difficulty or
inability manifested in mastication, and the consequent
cudding, arose from preternatural bluntness of the surfaces of
the molar teeth, which were, in consequence, filed, but without
beneficial result. It was after this that I saw the horse, and
I confess I was, at my first examination, quite as much at a
loss to offer any satisfactory interpretation as others had
been. While meditating, however, after my inspection, on the
apparently extraordinary nature of the case, it struck me that
I had not seen the tusks. I went back into the stable and
discovered two little tumors, red and hard, in the situation of
the inferior tusks, which, when pressed, gave the animal
insufferable pain. I instantly took out my pocketknife and made
crucial incisions through them both, down to the coming teeth,
from which moment the horse recovered his appetite and, by
degrees, his wonted condition.
The mouths of young horses should be examined from time to time to see
whether one or more of the milk teeth are not remaining too long,
causing the second teeth to grow in crooked, in which case the first
teeth should be removed with the forceps.
_Irregularities of teeth._--There is a fashion of late years, especially
in large cities, to have horses' teeth regularly "floated," or "rasped,"
by "veterinary dentists." In some instances this is very beneficial,
while in most cases it is entirely unnecessary. From the character of
the feed, the rubbing, or grinding, surface of the horse's teeth should
be rough. Still, we must remember that the upper jaw is somewhat wider
than the lower, and that, from the fact of the teeth not being perfectly
apposed, a sharp ridge is left unworn on the inside of the lower molars
and on the outside of the upper, which may excoriate the tongue or
cheeks to a considerable extent. This condition may readily be felt by
the hand, and these sharp ridges when found should be rasped down by a
guarded rasp. In some instances the first or last molar tooth is
unnaturally long, owing to the fact that its fellow in the opposite jaw
has been lost or does not close perfectly against it. Should it be the
last molar that is thus elongated, it will require the aid of the
veterinary surgeon, who has the necessary forceps or chisel for cutting
it. The front molar may be rasped down, if much patience is taken. In
decay of the teeth it is quite common to find the tooth corresponding to
the decayed one on the opposite jaw very much elongated, sometimes to
such an extent that the mouth can not be perfectly closed. Such teeth
must also be shortened by the tooth forceps, chisel, tooth saw, or rasp.
In all instances in which horses "quid" their feed, if they are
slobbering, or evince pain in mastication, shown by holding the head to
one side while chewing, the teeth should be carefully examined. Horses
whose teeth have unduly sharp edges are liable to drive badly; they pull
to one side, do not bear on the bit, or bear on too hard and "big," toss
the head, and start suddenly when a tender spot is touched. If, as is
mostly the case, all the symptoms are referable to sharp corners or
projections, these must be removed by the rasp. If decayed teeth ere
found, or other serious difficulty detected, or if the cause of the
annoying symptoms is not discovered, an expert should be called.
[Illustration: PLATE IV.
AGE OF HORSES AS INDICATED BY TEETH.
Longitudinal section of left central lower incisor and cross sections of
same tooth showing table surfaces as they appear at the ages of 3, 5, 7,
9, 15, 20 and 25 years. _C_, Cement; _D_, Dentine; _E_, Enamel; _I_,
Infundibulum; _K_, Cup; _P_, Pulp Cavity; _S_, Star.]
_Toothache._--This is rare in the horse and is mostly witnessed when
there is decay of a tooth or inflammation about its root. Toothache is
to be discovered in the horse by the pain expressed by him while feeding
or drinking cold water. I have seen horses, affected with toothache,
that would suddenly stop chewing, throw the head to one side, and
slightly open the mouth. They behave as though some sharp body had
punctured the mouth. If upon examination, no foreign body is found, we
must then carefully examine each tooth. If this can not be done with the
hand in the mouth, we can, in most instances, discover the aching tooth
by pressing each tooth from without. By tapping the teeth in succession
with a hard object, such as a small hammer, the one that is tender may
be identified. The horse will flinch when the sore tooth is pressed or
tapped upon. In most cases there is nothing to be done but extract the
decayed tooth, and this, of course, is to be attempted by the
veterinarian only.
_Deformity._--There is a deformity, known as parrot-mouth, that
interferes with prehension, mastication, and, indirectly, with
digestion. The upper incisors project in front of and beyond the lower
ones. The teeth of both jaws become unusually long, as they are not worn
down by friction. Such horses experience much difficulty in grazing.
Little can be done except to examine the teeth occasionally, and if
those of the lower jaw become so long that they bruise the "bars" of the
upper jaw, they must be shortened by the rasp or saw. Horses with this
deformity should never be left entirely at pasture.
The method of determining the age of a horse by the teeth is illustrated
in Plate IV.
DISEASES OF THE MOUTH.
LAMPAS.
Lampas is the name given to a swelling of the mucous membrane covering
the hard palate and projecting in a more or less prominent ridge
immediately behind the upper incisors. The hard palate is composed of
spongy tissue that fills with blood when the horse is feeding, which
causes the ridges to become prominent, and they then help to keep feed
from dropping from the mouth. This swelling is entirely natural and
occurs in every healthy horse. Where there is some irritation in the
mouth, as in stomatitis or during teething, the prominence of the hard
palate may persist, owing to the increased blood supply. In such cases
the cause of the irritation should be nought for and removed. By way of
direct treatment, slight scarification is the most that will be
required. Burning the lampas is barbarous and injurious, and it should
never be tolerated.
It is a quite common opinion among owners of horses and stablemen that
lampas is a disease that very frequently exists. In fact whenever a
horse fails to eat, and if he does not exhibit very marked symptoms of a
severe illness, they say at once "he has the lampas." It is almost
impossible to convince them to the contrary; yet it is not the case. It
may be put down, then, as an affliction of the stable-man's imagination
rather than of the horse's mouth.
STOMATITIS.
Stomatitis is an inflammation of the mucous membrane lining the mouth
and is produced by irritating medicines, feeds, or other substances. The
symptoms are swelling of the mouth, which is also hot and painful to the
touch; there is a copious discharge of saliva; the mucous membrane is
reddened, and in some cases vesicles or ulcers in the mouth are
observed. The treatment is simple, soft feed alone often being all that
is necessary. A bucket of fresh, cold water should be kept constantly in
the manger so that the horse may drink or rinse his mouth at will. In
some instances, it may be advisable to use a wash of chlorate of potash,
borax, or alum, about one-half ounce to a pint of water. Hay, straw, or
oats should not be fed unless steamed or boiled. A form of contagious
stomatitis, characterized by the formation within the mouth of small
vesicles, or blisters, sometimes occurs. In this disease the horse
should be isolated from other horses, and his stall, especially the feed
box, and his bit should be disinfected.
GLOSSITIS (INFLAMMATION OF THE TONGUE).
Glossitis, or inflammation of the tongue, is very similar to stomatitis,
and mostly exists with it and is due to the same causes. Injuries to the
tongue may produce this simple inflammation of its covering membrane,
or, if severe, may produce lesions much more extensive, such as
lacerations, abscesses, etc. These latter would require surgical
treatment, but for the simpler forms of inflammation of the tongue the
treatment recommended for stomatitis should be followed.
SALIVATION (PTYALISM).
Ptyalism, or salivation, consists in an abnormal and excessive secretion
of saliva. This is often seen as a symptom of irregular teeth;
inflammation of the mouth or tongue, or of the use of such medicines as
lobelia, mercury, and many others. Some feeds, such as clover, and
particularly second crop, produce it; foreign bodies, such as nails,
wheat chaff, and corncobs becoming lodged in the mouth, also are causes.
If the cause is removed no further attention is necessary, as a rule.
Astringent washes may be applied to the mouth as a gargle or by means of
a sponge.
PHARYNGITIS.
Pharyngitis is an inflammation of the mucous membrane lining of the
pharynx or throat. It rarely exists unless accompanied with stomatitis
or laryngitis, especially the latter. In those rare instances in which
the inflammation is mostly confined to the pharynx are noticed febrile
symptoms--difficulty of swallowing either liquids or solids; there is
but little cough except when trying to swallow; there is no soreness on
pressure over larynx (head of the windpipe). Increased flow of saliva,
difficulty of swallowing liquids in particular, and cough only when
attempting to swallow, are the symptoms best marked in pharyngitis. In
some cases the throat becomes gangrenous and the disease ends in death.
For treatment a wet sheet should be wrapped around the throat and
covered with rubber sheeting and a warm blanket. This should be changed
three times daily; or the region of the throat may be rubbed with
mercurial ointment twice daily until the skin becomes irritated, but no
longer; chlorate of potash may be given in 2-dram doses four times
daily, mixed with flaxseed meal or licorice-root powder and honey, as an
electuary. Soft feeds should be given, and fresh water should be
constantly before the horse.
PARALYSIS OF THE PHARYNX.
Paralysis of the pharynx, or, as it is commonly called, "paralysis of
the throat," is a rare but very serious disease. The symptoms are as
follows: The horse will constantly try to eat or drink, but will be
unable to do so; if water is offered him from a pail he will apparently
drink with avidity, but the quantity of water in the pail will remain
about the same; he will continue by the hour to try to drink; if he can
get any fluid into the back part of the mouth it will come out at once
through the nose. Feeds also return through the nose, or are dropped
from the mouth, quidded. An examination of the mouth by inserting the
hand fails to find any obstruction or any abnormal condition. These
cases go on from bad to worse; the horse constantly and rapidly loses in
condition, becomes very much emaciated, the eyes are hollow and
lusterless, and death occurs from inanition.
Treatment is very unsatisfactory. A severe blister should be applied
behind and under the jaw; the mouth is to be frequently swabbed out with
alum or chlorate of potash, 1 ounce to a pint of water, by means of a
sponge fastened to the end of a stick. Strychnia may be given in 1-grain
doses two or three times a day.
This disease may be mistaken at times for foreign bodies in the mouth or
for the so-called cerebrospinal meningitis. It is to be distinguished
from the former, upon a careful examination of the mouth, by the absence
of any offending body and by the flabby feel of the mouth, and from the
latter by the animal appearing in perfect health in every particular
except this inability to eat or drink.
ABSCESSES.
Abscesses sometimes form back of the pharynx and give rise to symptoms
resembling those of laryngitis or distemper. Interference with breathing
that is of recent origin and progression, without any observable
swelling or soreness about the throat, will make one suspect the
formation of an abscess in this location. But little can be done in the
way of treatment, save to hurry the ripening of the abscess and its
discharge by steaming with hops, hay, or similar substances and by
poulticing the throat. The operation for opening an abscess in this
region necessitates an intimate knowledge of the complex anatomy of the
throat region.
DISEASES OF THE ESOPHAGUS OR GULLET.
It is rare to find diseases of this organ, except as a result of the
introduction of foreign bodies too large to pass or to the administering
of irritating medicines. In the administration of irritant or caustic
medicines great care should be taken that they be thoroughly diluted. If
this is not done, erosions and ulcerations of the throat ensue, and this
again is prone to be followed by constriction (narrowing) of the gullet.
CHOKING.
The mechanical trouble of choking is quite common. It may occur when the
animal is suddenly startled while eating apples or roots, and we should
be careful never to approach suddenly or put a dog after horses or cows
that are feeding upon such substances. If left alone these animals very
rarely attempt to swallow the object until it is sufficiently
masticated.
Choking also arises from feeding oats in a deep, narrow manger to such
horses as eat very greedily or bolt their feed. Wheat chaff is also a
frequent cause of choke. This accident may result from the attempts to
force eggs down without breaking or from giving balls that are too large
or not of the proper shape.
Whatever object causes the choking, it may lodge in the upper part of
the esophagus, at its middle portion, or close to the stomach, giving
rise to the designations of pharyngeal, cervical, and thoracic choke. In
some cases where the original obstruction is low we find all that part
of the gullet above it to be distended with feed.
_Symptoms._--The symptoms vary somewhat according to the position of the
body causing choke. In pharyngeal choke the object is lodged in the
upper portion of the esophagus. The horse will present symptoms of great
distress, hurried breathing, frequent cough, excessive flow of saliva,
sweating, trembling, or stamping with the fore feet. The abdomen rapidly
distends with gas. The diagnosis is completed by manipulating the upper
part of the throat from without and by the introduction of the hand into
the back part of the mouth, finding the body lodged here. In cervical
choke (where the obstruction is situated at any point between the
throatlatch and the shoulder) the protrusion caused by the object can be
seen and the object can be felt. The symptoms here are not so severe;
the horse will be seen occasionally to draw himself up, arch his neck,
and make retching movements as though he wished to vomit. The abdomen
may be tympanitic. Should there be any question as to the trouble, a
conclusion may be reached by pouring water into the throat from a
bottle. If the obstruction is complete, by standing on the left side of
the horse and watching the course of the esophagus, you can see the
gullet, just above the windpipe, become distended with each bottle of
water. This is not always a sure test, as the obstruction may be an
angular body, in which case liquids would pass it. Solids taken would
show in these cases; solids should not, however, be given, as they serve
to increase the trouble by rendering the removal of the body more
difficult.
In thoracic choke the symptoms are less severe. Feed or water may be
ejected through the nose or mouth after the animal has taken a few
swallows. There will be some symptoms of distress, fullness of the
abdomen, cough, and occasionally retching movements. Sometimes a choking
horse is heard to emit groans. The facial expression always denotes
great anxiety and the eyes are bloodshot. The diagnosis is complete if,
upon passing the probang (a flexible tube made for this purpose), an
obstruction is encountered.
_Treatment._--If the choke is at the beginning of the gullet
(pharyngeal) an effort must be made to remove the obstacle through the
mouth. A mouthgag, or speculum, is to be introduced into the mouth to
protect the hand and arm of the operator. Then, while an assistant, with
his hands grasped tightly _behind_ the object, presses it upward and
forward with all his force, the operator must pass his hand into the
mouth until he can seize the obstruction and draw it outward. This mode
of procedure must not be abandoned with the first failure, as by
continued efforts we may get the obstacle farther toward the mouth. If
we fail with the hand, forceps may be introduced through the mouth and
the object seized when it is just beyond the reach of the fingers.
Should our efforts entirely fail, we must then endeavor to force the
obstruction downward by means of the probang. This instrument, which is
of such signal service in removing choke in cattle, is decidedly more
dangerous to use for the horse, and I can not pass this point without a
word of caution to those who have been known to introduce into the
horse's throat such objects as whipstalks, shovel handles, etc. These
are always dangerous, and more than one horse has been killed by such
barbarous treatment.
In cervical as well as in thoracic choke we must first of all endeavor
to soften or lubricate the obstruction by pouring oil or mucilaginous
drinks down the gullet. After this has been done endeavor to move the
object by gentle manipulations with the hands. If choked with oats or
chaff (and these are the objects that most frequently produce choke in
the horse), begin by gently squeezing the lower portion of the impacted
mass and endeavor to work it loose a little at a time. This is greatly
favored at times if we apply hot fomentations immediately about the
obstruction. Persist in these efforts for at least an hour before
deciding to resort to other and more dangerous modes of treatment. If
unsuccessful, however, the probang may be used. In the absence of the
regular instrument, a piece of inch hose 6 feet long or a piece of new
three-quarter-inch manila rope well wrapped at the end with cotton twine
and thoroughly greased with tallow should be used. The mouth is to be
kept open by a gag of wood or iron and the head slightly raised and
extended. The probang is then to be carefully guided by the hand into
the upper part of the gullet and gently forced downward until the
obstruction is reached. Pressure must then be gradual and firm. At first
too much force should not be used, or the esophagus will be ruptured.
Firm, gentle pressure should be kept up until the object is felt to
move, after which it should be followed rapidly to the stomach. If this
mode of treatment is unsuccessful, a veterinarian or a physician should
be called, who can remove the object by cutting down upon it. This
should scarcely be attempted by a novice, as a knowledge of the anatomy
of the parts is essential to avoid cutting the large artery, vein, and
nerve that are closely related to the esophagus in its cervical
portion.
Thoracic choke can be treated only by means of the introduction of oils
and mucilaginous drinks and the careful use of the probang.
STRICTURE OF THE ESOPHAGUS.
This is due to corrosive medicines, previous choking (accompanied with
lacerations, which, in healing, narrow the passage), or pressure on the
gullet by tumors. In the majority of cases of stricture, dilatation of
the gullet in front of the constricted portion soon occurs. This
dilatation is the result of the frequent accumulation of solid feed
above the constriction. Little can be done in either of these instances
except to give sloppy or liquid feed.
SACULAR DILATATION OF THE ESOPHAGUS.
This follows choking, and is due to stretching or rupture of the
muscular coat of the gullet, allowing the internal, or mucous, coat to
protrude through the lacerated muscular walls. Such a dilatation, or
pouch, may gradually enlarge from the frequent imprisonment of feed.
When liquids are taken, the solid materials are partially washed out of
the pouch.
The symptoms are as follows: The horse is able to swallow a few
mouthfuls without apparent difficulty; then he will stop feeding, paw,
contract the muscles of his neck, and eject a portion of the feed
through his nose or mouth, or it will gradually work down to the
stomach. As the dilatation thus empties itself the symptoms gradually
subside, only to reappear when he has again taken solid feed. Liquids
pass without any, or but little, inconvenience. Should this dilatation
exist in the cervical region, surgical interference may sometimes prove
effectual; if in the thoracic portion, nothing can be done, and the
patient rapidly passes from hand to hand by "swapping," until, at no
distant date, the contents of the sac become too firm to be dislodged as
heretofore, and the animal succumbs.
DISEASES OF THE STOMACH AND INTESTINES.
As a rule it is most difficult to distinguish between diseases of the
stomach and of the intestines of the horse. The reason for this is that
the stomach is relatively small. It lies away from the abdominal wall,
and so pressure from without can not be brought to bear upon it to
reveal sensitiveness or pain. Nor does enlargement, or distention, of
the stomach produce visible alteration in the form of the abdomen of the
horse. Moreover, it is a rule to which there are few exceptions, that an
irritant or cause of disease of the stomach acts likewise upon the
intestines, so that it is customary to find them similarly deranged. For
these reasons it is logical to discuss together the diseases of the
stomach and intestines and to point out such localizations in one organ
or another as are of importance in recognizing and treating the diseases
of the digestive organs of the horse.
It should be understood that gastritis signifies an inflammation of the
stomach and enteritis an inflammation of the intestines. The two terms
may be used together to signify a disease of the stomach and intestines,
as gastro-enteritis.
COLIC.
The disease of the horse that is most frequently met with is what is
termed "colic," and many are the remedies that are reputed to be "sure
cures" for this disease. Let us discover, then, what the word "colic"
means. This term is applied loosely to almost all diseases of the organs
of the abdomen that are accompanied with pain. If the horse evinces
abdominal pain, he probably will be considered as suffering with colic,
no matter whether the difficulty is a cramp of the bowel, an internal
hernia, overloading of the stomach, or a painful disease of the bladder
or liver. Since these conditions differ so much in their causation and
their nature, it is manifestly absurd to treat them alike and to expect
the same drugs or procedures to relieve them all. Therefore, it is
important that, so far as possible, the various diseased states that are
so roughly classed together as colic shall be separated and
individualized in order that appropriate treatments may be prescribed.
With this object in view, colics will be considered under the following
headings: (1) Engorgement colic, (2) obstruction colic, (3) flatulent or
tympanitic colic, (4) spasmodic colic. Worm colic is discussed under the
heading "Gastrointestinal parasites," page 90.
The general symptoms of abdominal pain, and therefore of colic, are
restlessness, cessation of whatever the horse is about, lying down,
looking around toward the flank, kicking with the hind feet upward and
forward toward the belly, jerky switching of the tail, stretching as
though to urinate, frequent change of position, and groaning. In the
more intense forms the horse plunges about, throws himself, rolls,
assumes unnatural positions, as sitting on the haunches, and grunts
loudly. Usually the pain is not constant, and during the intermissions
the horse may eat and appear normal. During the period of pain sweat is
poured out freely. Sometimes the horse moves constantly in a circle. The
respirations are accelerated, and usually there is no fever.
ENGORGEMENT COLIC.--This form of colic consists in an overloading of the
stomach with feed. The horse may have been overfed or the feed may have
collected in the stomach through failure of this organ to digest it and
pass it backward into the intestines. Even a normal quantity of feed
that the horse is unaccustomed to may cause disease. Hence a sudden
change of feed may produce engorgement colic. Continued full rations
while the horse is resting for a day or two or working too soon after
feeding may serve as a cause. New oats, corn, or hay, damaged feed, or
that which is difficult of digestion, such as barley or beans, may
incite engorgement colic. This disease may result from having fed the
horse twice by error or from its having escaped and taken an
unrestricted meal from the grain bin. Ground feeds that pack together,
making a sort of dough, may cause engorgement colic if they are not
mixed with cut hay. Greedy eaters are predisposed to this disease.
_Symptoms._--The horse shows the general signs of abdominal pain, which
may be long continued or of short duration. Retching or vomiting
movements are made; these are shown by labored breathing, upturned upper
lip, contraction of the flank, active motion at the throat, and drawing
in of the nose toward the breast, causing high arching of the neck. The
horse may assume a sitting position like a dog. At times the pain is
very great and the horse makes the most violent movements, as though
mad. At other times there is profound mental depression, the horse
standing in a sleepy, or dazed, way, with the head down, the eyes
closed, and leaning his head against the manger or wall. There is,
during the struggles, profuse perspiration. Following retching, gas may
escape from the mouth, and this may be followed by a sour froth and some
stomach contents. The horse can not vomit except when the stomach is
violently stretched, and, if the accumulation of feed or gas is great
enough to stretch the stomach so that vomiting is possible, it may be
great enough to rupture that organ. So it happens not infrequently that
a horse dies from ruptured stomach after vomiting. After the stomach
ruptures, however, vomiting is impossible. The death rate in this form
of colic is high.
_Treatment._--The bowels should be stimulated to contraction by the use
of clysters of large quantities of water and of glycerin. Veterinarians
use hypodermic injections of eserin or arecolin or intravenous
injections of barium chlorid, but they must be employed with great
caution. It is not profitable to give remedies by the stomach, for they
can not be absorbed. But small doses of morphin (5 grains) or of the
fluid extract of Indian hemp (2 drams) may be placed in the mouth and
are absorbed in part, at least, without passing to the stomach. These
drugs lessen pain and thus help to overcome the violent movements that
are dangerous, because they may be the means of causing rupture of the
diaphragm or stomach. If facilities are available, relief may be
afforded by passing an esophageal tube through which some of the gaseous
and liquid contents of the stomach may escape.
_Rupture of the stomach._--This mostly occurs as a result of engorged or
tympanitic stomach (engorgement colic) and from the horse violently
throwing himself when so affected. It may result from disease of the
coats of the stomach, gastritis, stones (calculi), tumors, or anything
that closes the opening of the stomach into the intestines, and very
violent pulling or jumping immediately after the animal has eaten
heartily of bulky feed. These or similar causes may lead this accident.
The symptoms of rupture of the stomach are not constant or always
reliable. Always make inquiry as to what and how much the horse has been
fed at the last meal. Vomiting may precede rupture of this organ, as
stated above. This accident appears to be most liable to occur in heavy
draft horses. A prominent symptom observed (though it may also occur in
diaphragmatic hernia) is when the horse, if possible, gets the front
feet on higher ground than the hind ones or sits on his haunches, like a
dog. This position affords relief to some extent, and it will be
maintained for several minutes; it is also quickly regained when the
horse has changed it for some other. Colicky symptoms, of course, are
present, which vary much and present no diagnostic value. As the case
progresses the horse will often stretch forward the fore legs, lean
backward and downward until the belly nearly touches the ground, and
then rise up again with a groan, after which the fluid from his nostrils
is issued in increased quantity. The pulse is fast and weak, breathing
hurried, body bathed in a clammy sweat, limbs tremble violently, the
horse reels or staggers from side to side, and death quickly ends the
scene.
In the absence of any pathognomonic symptom we must consider the history
of the case; the symptoms of colic that cease suddenly and are succeeded
by cold sweats and tremors; the pulse quick and small and thready,
growing weak and more frequent, and at length running down and becoming
altogether imperceptible; looking back at the flank and groaning;
sometimes crouching with the hind quarters; with or without eructation
and vomiting.
There is no treatment that can be of any use whatever. Could we be sure
of our diagnosis it would be better to destroy the animal at once.
Since, however, there is always the possibility of a mistake in
diagnosis, we may give powdered opium in 1-dram doses every two or three
hours, with the object of keeping the stomach as quiet as possible.
OBSTRUCTION COLIC.--The stomach or bowels may be obstructed by
accumulations of partly digested feed (fecal matter), by foreign bodies,
by displacements, by paralysis, or by abnormal growths.
_Impaction of the large intestines._--This is a very common bowel
trouble and one which, if not promptly recognized and properly treated,
results in death. It is caused by overfeeding, especially of bulky feed
containing an excess of indigestible residue; old, dry, hard hay, or
stalks when largely fed; deficiency of secretions of the intestinal
tracts; lack of water; want of exercise, medicines, etc.
Impaction of the large bowels is to be diagnosed by a slight abdominal
pain, which may disappear for a day or two to reappear with more
violence. The feces are passed somewhat more frequently, but in smaller
quantities and drier; the abdomen is full, but not distended with gas;
the horse at first is noticed to paw and soon begins to look back at his
sides. Probably one of the most characteristic symptoms is the position
assumed when down. He lies flat on his side, head and legs extended,
occasionally raising his head to look toward his flank; he remains on
his side for from five to fifteen minutes at a time. Evidently this
position is the one giving the most freedom from pain. He rises at
times, walks about the stall, paws, looks at his sides, backs up against
the stall, which he presses with his tail, and soon lies down again,
assuming his favored position. The intestinal sounds, as heard by
applying the ear to the flank, are diminished, or there is no sound,
indicating absence of motion of the bowels. The bowels may cease
entirely to move. The pressure of the distended intestine upon the
bladder may cause the horse to make frequent attempts to urinate. The
pulse is but little changed at first, being full and sluggish; later, if
this condition is not overcome, it becomes rapid and feeble. Horses may
suffer from impaction of the bowels for a week, yet eventually recover,
and cases extending two or even three weeks have ended favorably. As a
rule, however, they seldom last more than four or five days, many, in
fact, dying sooner than this.
The treatment consists of efforts to produce movement of the bowels and
to prevent inflammation of the same from arising. A large cathartic is
to be given as early as possible. Either of the following is
recommended: Powdered Barbados aloes 1 ounce, calomel 2 drams, and
powdered nux vomica 1 dram; or linseed oil 1 pint and croton oil 15
drops; or from 1 pint to 1 quart of castor oil may be given. Some favor
the administration of Epsom or Glauber's salt, 1 pound, with one-quarter
pound of common salt, claiming that this causes the horse to drink
largely of water, thus mechanically softening the impacted mass and
favoring its expulsion. Whichever physic is selected, it is essential
that a full dose be given. This is much better than small and repeated
doses. It must be borne in mind that horses require about twenty-four
hours in which to respond to a physic, and under no circumstances is it
to be repeated sooner. If aloes has been given and has failed to operate
at the proper time, oil or some different cathartic should then be
administered. Allow the horse all the water he will drink. Calomel may
be administered in half-dram doses, the powder being placed on the
tongue, one dose every two hours until four doses are given.
Enemas of glycerin, 2 to 4 ounces, are often beneficial. Rubbing or
kneading of the abdominal walls and the application of stimulating
liniments or strong mustard water also, at times, favor the expulsion of
this mass. Walking exercise must occasionally be given. If this
treatment is faithfully carried out from the start the majority of cases
will terminate favorably. When relief is not obtained inflammation of
the bowels may ensue and cause death.
_Constipation, or costiveness._--This is often witnessed in the horse,
and particularly in the foal. Many colts die every year from failure on
the part of the attendant to note the condition of the bowels soon after
birth. Whenever the foal fails to pass any feces, and in particular if
it presents any signs of colicky pains--straining, etc.--immediate
attention must be given it. As a rule, it will be necessary only to give
a few injections of soapy water in the rectum and to introduce the
finger through the anus to break down any hardened mass of dung found
there. If this is not effective a purgative must be given. Oils are the
best for these young animals, and preferably castor oil, giving from 2
to 4 ounces. The foal should always get the first of the mother's milk,
which, for a few days, possesses decidedly laxative properties. If a
mare, while suckling, is taking laudanum, morphin, atropia, or similar
medicines, the foal during this time should be fed by hand and the mare
milked upon the ground. Constipation in adult horses is often the result
of long feeding on dry, innutritious feed, deficiency of intestinal
secretions, scanty water supply, or lack of exercise. If the case is not
complicated with colicky symptoms a change to light, sloppy diet,
linseed gruel or tea, with plenty of exercise, is all that is required.
If colic exists a cathartic is needed. In very many instances the
constipated condition of the bowels is due to lack of intestinal
secretions, and when so caused may be treated by giving fluid extract of
belladonna in 2-dram doses three times a day and handful doses of Epsom
salt daily in the feed. It is always best, when possible, to overcome
this trouble by a change of diet rather than by the use of medicines.
For the relief of constipation such succulent feeds as roots, grass, or
green forage are recommended. Silage, however, should be fed sparingly,
and not at all unless it is in the very best condition. Moldy silage may
cause fatal disease.
_Foreign bodies (calculi, stones) in the stomach._--There are probably
but few symptoms exhibited by the horse that will lead one to suspect
the presence of gastric calculi, and possibly none by which we can
unmistakably assert their presence. They have been found most frequently
in millers' horses fed sweepings from the mills. A depraved and
capricious appetite is common in horses that have a stone forming in the
stomachs. There is a disposition to eat the woodwork of the stable,
earth, and, in fact, almost any substance within their reach. This
symptom must not, however, be considered as pathognomonic, since it is
observed when calculi are not present. Occasional colics may result from
these "stomach stones," and when the latter lodge at the outlet of the
stomach they may give rise to symptoms of engorged stomach, already
described. There is, of course, no treatment that will prove effective.
Remedies to move the bowels, to relieve pain, and to combat inflammation
should be given.
_Intestinal concretions (calculi or stones in the intestines)._--These
concretions are usually found in the large bowels, though they are
occasionally seen in the small intestines. They are of various sizes,
weighing from 1 ounce to 25 pounds; they may be single or multiple, and
differ in composition and appearance, some being soft (composed mostly
of animal or vegetable matter), while others are porous, or honeycombed
(consisting of animal and mineral matter), and others are entirely hard
and stonelike. The hair balls, so common to the stomach and intestines
of cattle, are very rare in horses. Intestinal calculi form around some
foreign body, as a rule--a nail or piece of wood--whose shape they may
assume to a certain extent. Layers are arranged concentrically around
such nucleus until the sizes above spoken of are attained. These stones
are also often found in millers' horses, as well also as in horses in
limestone districts, where the water is hard. When the calculi attain a
sufficient size and become lodged or blocked in some part of the
intestines, they cause obstruction, inflammation of the bowels, colicky
symptoms, and death. There are no certain signs or symptoms that reveal
them. Recurring colics of the type of impaction colic, but more severe,
may lead one to suspect the existence of this condition. Examination
through the rectum may reveal the calculus.
The symptoms will be those of obstruction of the bowels. Upon
post-mortem examinations these stones will be discovered mostly in the
large bowels; the intestines will be inflamed or gangrenous about the
point of obstruction. Sometimes calculi have been expelled by the action
of a physic, or they may be removed by the hand when found to occupy the
rectum.
As in concretions of the stomach, but little can be done in the way of
treatment more than to overcome spasm (if any exists), and to give
physics with the hope of dislodging the stone or stones and carrying
them on and outward.
_Intussusception, or invagination._--This is the slipping of a portion
of the intestine into another portion immediately adjoining, like a
partially turned glove finger. This may occur at any part of the bowels,
but is most frequent in the small guts. The invaginated portion may be
slight--2 or 3 inches only--or extensive, measuring as many feet. In
intussusception, the inturned bowel is in the direction of the anus.
There are adhesions of the intestines at this point, congestion,
inflammation, or even gangrene. This accident is most liable to occur in
horses that are suffering from spasm of the bowel, or in those in which
a small portion of the gut is paralyzed. The natural wormlike or
ringlike contraction of the gut favors the passage of the contracted or
paralyzed portion into that immediately behind it. It may occur during
the existence of almost any abdominal trouble, as diarrhea, inflammation
of the bowels, or from injuries, exposure to cold, etc. A fall or
leaping may give the initial maldirection. Foals are most likely to be
thus afflicted.
Unless the invaginated portion of the gut becomes strangulated, probably
no symptoms except constipation will be appreciable. Strangulation of
the bowel may take place suddenly, and the horse die within 24 hours, or
it may occur after several days--a week even--and death then follow.
There are no symptoms positively diagnostic. Colicky pains, more or less
severe and continuous, are observed, and at first there may be diarrhea,
followed by constipation. Severe straining occurs in some instances of
intussusception, and when this occurs it should receive due credit. As
death approaches, the horse sweats profusely, sighs, presents an anxious
countenance, the legs and ears become cold, and there is often freedom
from pain immediately before death. In some rare instances he recovers,
even though the invaginated portion of the gut has become strangulated.
In this case the imprisoned portion sloughs away so gradually that a
union has taken place between the intestines at the point where one
portion has slipped into that behind it. The piece sloughing off is
found passed with the manure. Such cases are exceedingly rare.
Nonirritating laxatives, such as castor oil, sweet oil, or calomel in
small doses, should be given. Soft feed and mucilaginous and nourishing
drinks should be given during these attacks. E. Mayhew Michener has
operated successfully on a foal with intussusception by opening the
abdomen and releasing the imprisoned gut.
_Volvulus, gut tie, or twisting of the bowels._--These are the terms
applied to the bowels when twisted or knotted. This accident is rather a
common one, and frequently results from the violent manner in which a
horse throws himself about when attacked by spasmodic colic. The
symptoms are the same as those of intussusception and obstructions of
the bowels; the same directions as to treatment are therefore to be
observed.
_Paralysis of the intestine._--This occurs in old, debilitated animals
that have been fed on coarse, innutritious fodder. This produces a
condition of dilatation so pronounced as to make it impossible for the
intestine to advance its contents, and so obstruction results. The
symptoms are as in other forms of obstruction colic. The history of the
case is of much service in diagnosing the trouble. The treatment
consists in the administration of laxatives. One may give 1 quart of raw
linseed oil and follow it the next day with 1 pound of Glauber's salt
dissolved in a quart of warm water. Strychnia may be given in doses of 1
grain two or three times daily. If the stagnant mass of feces is in the
rectum, it must be removed with the hand.
_Abnormal growths_, such as tumors or fibrous tissue, producing
contraction or stricture, may be causes of obstruction. The colic caused
by these conditions is chronic. The attacks occur at gradually
shortening intervals and become progressively more severe. Relief is
afforded by the use of purgatives that render the feces soft and thin
and thus enable them to pass the obstruction, but in time the contracted
place is liable to close so far that passage is impossible and the horse
will die.
FLATULENT COLIC (TYMPANITIC COLIC, WIND COLIC, OR BLOAT).--Among the
most frequent causes of this form of colic are to be mentioned sudden
changes of feed, too long fasting and feed then given while the animal
is exhausted, new hay or grain, large quantities of feed that is green
or that has lain in the manger for some time and become sour,
indigestible feed, irregular teeth, crib biting, and, in fact, anything
that produces indigestion may produce flatulent colic.
_Symptoms._--The symptoms of wind colic are not so suddenly developed
nor so severe as those of cramp colic. At first the horse is noticed to
be dull, paws slightly, and may or may not lie down. The pains from the
start are continuous. The belly enlarges, and by striking it in front of
the haunches a drumlike sound results. If not soon relieved the above
symptoms are aggravated, and in addition difficult breathing, bloodshot
eyes, and red mucous membranes, loud tumultuous heart beat, profuse
perspiration, trembling of front legs, sighing respiration, staggering
from side to side are noticed, and, finally, plunging forward dead. The
diagnostic symptom of flatulent colic is the distention of the bowels
with gas, detected by the bloated appearance and resonance on
percussion.
_Treatment._--The treatment for wind colic differs very greatly from
that of cramp colic. Absorbents are of some service, and charcoal may be
given in any quantity. Relaxants and antispasmodics are also beneficial
in this form of colic. Chloral hydrate not only possesses these
qualities, but it also is an antiferment and a pain reliever. It is,
then, particularly well adapted to the treatment of wind colic, and
should be given in the same-sized doses and in the manner directed for
spasmodic colic. Diluted alcohol or whisky may be given, or aromatic
spirits of ammonia in 1-ounce doses at short intervals.
A physic should always be given as early as possible in flatulent colic,
the best being Barbados aloes in the dose already mentioned. Injections,
per rectum, of turpentine 1 to 2 ounces, linseed oil 8 ounces, may be
given frequently to stimulate the peristaltic motion of the bowels and
to favor the escape of wind. Blankets wrung out of hot water do much to
afford relief; they should be renewed every 5 or 10 minutes and covered
with a dry woolen blanket. This form of colic is much more fatal than
cramp colic, and requires prompt and persistent treatment. It is
entirely unsafe to predict the result, some apparently mild attacks
going on to speedy death, while others that at the onset appear to be
very severe yielding rapidly to treatment. No efforts should be spared
until the animal is known to be dead. In these severe cases puncturing
of the bowels in the most prominent (distended) part by means of a small
trocar and cannula or with a needle of a hypodermic syringe, thus
allowing the escape of gas, has often saved life, and such punctures, if
made with a clean, sharp instrument that is not allowed to remain in the
horse too long, are accompanied with little danger and do more to
relieve the patient quickly than any other treatment.
SPASMODIC OR CRAMP COLIC.--This is the name given to that form of colic
produced by contraction, or spasm, of a portion of the small intestines.
It is produced by indigestible feed; large drinks of cold water when the
animal is warm; driving a heated horse through deep streams; cold rains;
drafts of cold air, etc. Unequal distribution of or interference with
the nervous supply here produces cramp of the bowels, the same as
external cramps are produced. Spasmodic colic is much more frequently
met with in high-bred, nervous horses than in coarse, lymphatic ones.
_Symptoms._--These should be carefully studied in order to diagnose this
from other forms of colic requiring quite different treatment. Spasmodic
colic always begins suddenly. If feeding, the horse is seen to stop
abruptly, stamp impatiently, and probably look back. He soon evinces
more acute pain, shown by pawing, suddenly lying down, rolling, and
getting up. During the period of pain the intestinal sounds, as heard by
applying the ear over the flank, are louder than in health. There is
then an interval of ease; he will resume feeding and appear to be
entirely well. In a little while, however, the pains return and are
increased in severity, only to pass off again for a time. As the attack
progresses these intervals of ease become shorter and shorter, and pain
may be continuous, though even then there are exacerbations of pain.
Animals suffering from this form of colic evince the most intense pain;
they throw themselves, roll over and over, jump up, whirl about, drop
down again, paw, or strike rather, with the front feet, steam and sweat,
and make frequent attempts to pass their urine. Only a small quantity of
water is passed at a time; this is due to the bladder being so
frequently emptied. These attempts to urinate are often regarded by
horsemen as symptoms of trouble of the kidneys or bladder. In reality
they are only one of the many ways in which the horse expresses the
presence of pain. As a matter of fact, diseases of the bladder or
kidneys of the horse are exceedingly rare.
To recapitulate the symptoms of spasmodic colic: The history of the
case, the type of horse, the suddenness of the attack, the increased
intestinal sounds, the intervals of ea
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