Produced by Charles Aldarondo, Tiffany Vergon, Beth Trapaga,
Charles Franks and the Online Distributed Proofreading Team.
COMMON DISEASES OF FARM ANIMALS
By R. A. Craig, D.V.M.
[Illustration: Frontispiece--INSANITARY DAIRY STABLE AND YARDS. DISEASE AND
FINANCIAL LOSS ARE TO BE EXPECTED WHEN FARM ANIMALS ARE KEPT IN FILTHY,
INSANITARY QUARTERS]
PREFACE
In preparing the material for this book, the author has endeavored to
arrange and discuss the subject matter in a way to be of the greatest
service and help to the agricultural student and stockman, and place at
their disposal a text and reference book.
The general discussions at the beginning of the different sections and
chapters, and the discussions of the different diseases are naturally
brief. An effort has been made to conveniently arrange the topics for both
practical and class-room work. The chapters have been grouped under the
necessary heads, with review questions at the end of each chapter, and the
book divided into seven parts.
The chapters on diseases of the locomotory organs, the teeth, surgical
diseases and castration, although not commonly discussed in books of this
class, the writer believes will be of value for reference and instructional
work.
When used as a text-book, it will be well for the instructor to supplement
the text with class-room discussions.
The writer has given special emphasis to the cause and prevention of
disease, and not so much to the medicinal treatment. Stockmen are not
expected to practise the medicinal treatment, but rather the preventive
treatment of disease. For this reason it is not deemed advisable to give a
large number of formulas for the preparation of medicinal mixtures to be
used for the treatment of disease, but such treatment is suggested in the
most necessary cases.
R. A. CRAIG.
PURDUE UNIVERSITY, LaFayette, Ind. August, 1915.
CONTENTS
PART I.--INTRODUCTORY.
I. GENERAL DISCUSSION OF DISEASE
II. DIAGNOSIS AND SYMPTOMS OF DISEASE
III. TREATMENT
PART II.--NON-SPECIFIC OR GENERAL DISEASES.
IV. DISEASES OF THE DIGESTIVE SYSTEM
V. DISEASES OF THE LIVER
VI. DISEASES OF THE URINARY ORGANS
VII. DISEASES OF THE GENERATIVE ORGANS
VIII. DISEASES OF THE RESPIRATORY APPARATUS
IX. DISEASES OF THE CIRCULATORY ORGANS
X. DISEASES OF THE NERVOUS SYSTEM
XI. DISEASES OF THE SKIN
XII. DISEASES OF THE EYE
XIII. GENERAL DISEASES OF THE LOCOMOTORY APPARATUS
XIV. STRUCTURE OF THE LIMBS OF THE HORSE
XV. UNSOUNDNESSES AND BLEMISHES
XVI. DISEASES OF THE FORE-LIMB
XVII. DISEASES OF THE FOOT
XVIII. DISEASES OF THE HIND LIMB
PART III.--THE TEETH.
XIX. DETERMINING THE AGE OF ANIMALS
XX. IRREGULARITIES OF THE TEETH
PART IV.--SURGICAL DISEASES.
XXI. INFLAMMATION AND WOUNDS
XXII. FRACTURES AND HARNESS INJURIES
XXIII. COMMON SURGICAL OPERATIONS
PART V.--PARASITIC DISEASES.
XXIV. PARASITIC INSECTS AND MITES
XXV. ANIMAL PARASITES
PART VI.--INFECTIOUS DISEASES.
XXVI. HOG-CHOLERA
XXVII. TUBERCULOSIS
XXVIII. INFECTIOUS DISEASES COMMON TO THE DIFFERENT SPECIES OF DOMESTIC
ANIMALS
XXIX. INFECTIOUS DISEASES OF THE HORSE
XXX. INFECTIOUS DISEASES OF CATTLE
XXXI. INFECTIOUS DISEASES OF POULTRY
REFERENCE BOOKS
ILLUSTRATIONS
FIG.
(Frontispiece) Insanitary dairy stable and yards.
1. Side and posterior view of bull showing conformation favorable to the
development of disease.
2. Insanitary yards.
3. Showing where pulse of horse is taken.
4. Auscultation of the lungs.
5. Fever thermometer.
6. Dose syringe.
7. Hypodermic syringes.
8. Photograph of model of horse's stomach.
9. Photograph of model of stomach of ruminant.
10. Oesophageal groove.
11. Dilated stomach of horse.
12. Rupture of stomach of horse.
13. Showing the point where the wall of flank and rumen are punctured
with trocar and cannula in "bloat".
14. Photograph of model of digestive tract of horse.
15. Photograph of model of digestive tract of ruminant.
16. A yearling colt that died of aneurism colic.
17. Photograph of model of udder of cow.
18. Photograph of model of uterus of cow containing foetus.
19. Placenta of cow.
20. A case of milk-fever.
21. Milk-fever apparatus.
22. A case of catarrhal cold.
23. Photograph of model of horse's heart.
24. Elephantiasis in horse.
25. Photograph of model of horse's brain.
26. Unilateral facial paralysis.
27. Bilateral facial paralysis.
28. Skeleton of horse.
29. Photograph of model of stifle joint.
30. Atrophy of the muscles of the thigh.
31. Shoulder lameness.
32. Shoe-boil.
33. Sprung knees.
34. Splints.
35. Bones of digit.
36. Photograph of a model of the foot.
37. Foot showing neglect in trimming wall.
38. A very large side bone.
39. A case of navicular disease.
40. An improperly shod foot.
41. Toe-cracks.
42. Quarter-crack caused by barb-wire cut.
43. Changes occurring in chronic laminitis.
44. Atrophy of the muscles of the quarter.
45. String-halt.
46. A large bone spavin.
47. Normal cannon bone and cannon bone showing bony enlargement.
48. Bog spavins.
49. Thorough pin.
50. Curbs.
51. Head of young horse showing position and size of teeth.
52. Longitudinal section of incisor tooth.
53. Cross-section of head of young horse, showing replacement of molar
tooth.
54. Transverse section of incisor tooth
55. Transverse sections of incisor tooth showing changes at different
ages.
56. Teeth showing uneven wear occurring in old horses.
57. Fistula of jaw.
58. A large hock caused by a punctured wound of the joint.
59. A large inflammatory growth following injury.
60. Fistula of the withers.
61. Shoulder abscess caused by loose-fitting harness.
62. A piece of the wall of the horse's stomach showing bot-fly larvae
attached.
63. Biting louse.
64. Sucking louse.
65. Nits attached to hair.
66. Sheep-tick.
67. Sheep scab mite.
68. Sheep scab.
69. A severe case of mange.
70. Liver flukes.
71. Tapeworm larvae in liver.
72. Tapeworms.
73. Tapeworm larvae in the peritoneum.
74. Thorn-headed worms.
75. Large round-worm in intestine of hog.
76. Lamb affected with stomach worm disease.
77. Whip-worms attached to wall of intestine.
78. Pin-worms in intestine.
79. A hog yard where disease-producing germs may be carried over
from year to year.
80. Carcass of a cholera hog.
81. Kidneys from hog that died of acute hog-cholera.
82. Lungs from hog that died of acute hog-cholera.
83. A piece of intestine showing intestinal ulcers.
84. Cleaning up a hog lot.
85. Hyperimmune hogs used for the production of anti-hog-cholera serum.
86. Preparing the hog for vaccination.
87. Vaccinating a hog.
88. Koch's _Bacillus tuberculosis_.
89. A tubercular cow.
90. Tubercular spleens.
91. The carcass of a tubercular cow.
92. A section of the chest wall of a tubercular cow.
93. A very large tubercular gland.
94. A tubercular gland that is split open.
95. Caul showing tuberculosis.
96. Foot of hog showing tuberculosis of joint.
97. _Staphylococcus pyogenes_.
98. _Streptococcus pyogenes_.
99. Bacillus of malignant oedema, showing spores.
100. Bacillus of malignant oedema.
101. _Bacillus bovisepticus_.
102. A yearling steer affected with septicaemia haemorrhagica.
103. _Bacillus anthracis_.
104. _Bacillus necrophorus_.
105. Negri bodies in nerve-tissue.
106. A cow affected with foot-and-mouth disease.
107. Slaughtering a herd of cattle affected with foot-and-mouth disease.
108. Disinfecting boots and coats before leaving a farm where cattle have
been inspected for foot-and-mouth disease.
109. Cleaning up and disinfecting premises.
110. _Bacillus tetani_.
111. Head of horse affected with tetanus.
112. A subacute case of tetanus.
113. Streptococcus of strangles.
114. _Bacillus mallei_.
115. Nasal septum showing nodules and ulcers.
116. _Streptococcus pyogenes equi_.
117. A case of "lumpy jaw".
118. The ray fungus.
119. Bacillus of emphysematous anthrax.
120. Cattle tick (male).
121. Cattle tick (female).
122. Blood-cells with _Piroplasma bigeminum_ in them.
123. _Bacillus avisepticus_.
PART I.--INTRODUCTORY
CHAPTER I
GENERAL DISCUSSION OF DISEASE
Disease is the general term for any deviation from the normal or healthy
condition of the body. The morbid processes that result in either slight or
marked modifications of the normal condition are recognized by the
injurious changes in the structure or function of the organ, or group of
body organs involved. The increase in the secretion of urine noticeable in
horses in the late fall and winter is caused by the cool weather and the
decrease in the perspiration. If, however, the increase in the quantity of
urine secreted occurs independently of any normal cause and is accompanied
by an unthrifty and weakened condition of the animal, it would then
characterize disease. Tissues may undergo changes in order to adapt
themselves to different environments, or as a means of protecting
themselves against injuries. The coat of a horse becomes heavy and appears
rough if the animal is exposed to severe cold. A rough, staring coat is
very common in horses affected by disease. The outer layer of the skin
becomes thickened when subject to pressure or friction from the harness.
This change in structure is purely protective and normal. In disease the
deviation from normal must be more permanent in character than it is in the
examples mentioned above, and in some way prove injurious to the body
functions.
CLASSIFICATION.--We may divide diseases into three classes: _non-specific,
specific_ and _parasitic_.
_Non-specific diseases_ have no constant cause. A variety of causes may
produce the same disease. For example, acute indigestion may be caused by a
change of diet, watering the animal after feeding grain, by exhaustion and
intestinal worms. Usually, but one of the animals in the stable or herd is
affected. If several are affected, it is because all have been subject to
the same condition, and not because the disease has spread from one animal
to another.
_Specific Diseases._--The terms infectious and contagious are used in
speaking of specific diseases. Much confusion exists in the popular use of
these terms. A _contagious_ disease is one that may be transmitted by
personal contact, as, for example, influenza, glanders and hog-cholera. As
these diseases may be produced by indirect contact with the diseased animal
as well as by direct, they are also _infectious_. There are a few germ
diseases that are not spread by the healthy animals coming in direct
contact with the diseased animal, as, for example, black leg and southern
cattle fever. These are purely infectious diseases. Infection is a more
comprehensive term than contagion, as it may be used in alluding to all
germ diseases, while the use of the term contagion is rightly limited to
such diseases as are produced principally through individual contact.
_Parasitic diseases_ are very common among domestic animals. This class of
disease is caused by insects and worms, as for example, lice, mites, ticks,
flies, and round and flat worms that live at the expense of their hosts.
They may invade any of the organs of the body, but most commonly inhabit
the digestive tract and skin. Some of the parasitic insects, mosquitoes,
flies and ticks, act as secondary hosts for certain animal microorganisms
that they transmit to healthy individuals through the punctures or the
bites that they are capable of producing in the skin.
CAUSES.--For convenience we may divide the causes of disease into the
predisposing or indirect, and the exciting or direct.
_The predisposing causes_ are such factors as tend to render the body more
susceptible to disease or favor the presence of the exciting cause. For
example, an animal that is narrow chested and lacking in the development of
the vital organs lodged in the thoracic cavity, when exposed to the same
condition as the other members of the herd, may contract disease while the
animals having better conformation do not (Fig. 1). Hogs confined in
well-drained yards and pastures that are free from filth, and fed in pens
and on feeding floors that are clean, do not become hosts for large numbers
of parasites. Hogs confined in filthy pens are frequently so badly infested
with lice and intestinal worms that their health and thriftiness are
seriously interfered with. In the first case mentioned the predisposition
to disease is in the individual, and in the second case it is in the
surroundings (Fig. 2).
[Illustration: FIG. 1.--Side and posterior view of bull showing
conformation favorable to the development of disease.]
_The exciting causes_ are the immediate causes of the particular disease.
Exciting causes usually operate through the environment. With the exception
of the special disease-producing germs, the most common exciting causes are
faulty food and faulty methods of feeding. The following predisposing
causes of disease may be mentioned:
_Age_ is an important factor in the production of disease. Young and
immature animals are more prone to attacks of infectious diseases than are
old and mature animals. Hog-cholera usually affects the young hogs in the
herd first, while scours, suppurative joint disease and infectious sore
mouth are diseases that occur during the first few days or few weeks of the
animal's life. Lung and intestinal parasites are more commonly found in the
young, growing animals. Old animals are prone to fractures of bones and
degenerative changes of the body tissues. As a general rule, the young are
more subject to acute diseases and the old to chronic diseases.
[Illustration: FIG. 2.--Insanitary yards.]
_The surroundings or environments_ are important predisposing factors. A
dark, crowded, poorly ventilated stable lowers the animal's vitality, and
renders it more susceptible to the disease. A few rods difference in the
location of stables and yards may make a marked difference in the health of
the herd. A dry, protected site is always preferable to one in the open or
on low, poorly drained soil. The majority of domestic animals need but
little shelter, but they do need dry, comfortable quarters during wet, cold
weather.
_Faulty feed and faulty methods of feeding_ are very common causes of
diseases of the digestive tract and the nervous system. A change from dry
feed to a green, succulent ration is a common cause of acute indigestion in
both horses and cattle. The feeding of a heavy ration of grain to horses
that are accustomed to exercise, during enforced rest may cause liver and
kidney disorders. The feeding of spoiled, decomposed feeds may cause
serious nervous and intestinal disorders.
_One attack of a certain disease_ may influence the development of
subsequent attacks of the same, or a different disease. An individual may
suffer from an attack of pneumonia that so weakens the disease-resisting
powers of the lungs as to result in a tubercular infection of these organs.
In the horse, one attack of azoturia predisposes it to a second attack. One
attack of an infectious disease usually confers immunity against that
particular disease. _Heredity_ does not play as important a part in the
development of diseases in domestic animals as in the human race. A certain
family may inherit a predisposition to disease through the faulty or
insufficient development of an organ or group of organs. The different
species of animals are affected by diseases peculiar to that particular
species. The horse is the only species that is affected with azoturia.
Glanders affects solipeds, while black leg is a disease peculiar to cattle.
QUESTIONS
1. What is disease?
2. How are diseases classified? Give an example of the different classes.
3. What is a predisposing cause? Exciting cause?
4. Name the different predisposing and exciting causes of disease.
CHAPTER II
DIAGNOSIS AND SYMPTOMS OF DISEASE
The importance of recognizing or diagnosing the seat and nature of the
morbid change occurring in an organ or group of organs cannot be
overestimated. Laymen do not comprehend the difficulty or importance of
correctly grouping the signs or symptoms of disease in such a way as to
enable them to recognize the nature of the disease. In order to be able to
understand the meaning of the many symptoms or signs of disease, we must
possess knowledge of the structure and physiological functions of the
different organs of the body. We must be familiar with the animal when it
is in good health in order to be able to recognize any deviation from the
normal due to disease, and we must learn from personal observation the
different symptoms that characterize the different diseases. Stockmen
should be able to tell when any of the animals in their care are sick as
soon as the first symptom of disease manifests itself, by changes in the
general appearance and behavior. But in order to ascertain the exact
condition a general and systematic examination is necessary. The examiner,
whether he be a layman or a veterinarian, must observe the animal
carefully, noting the behavior, appearance, surroundings, and general and
local symptoms.
Before making a _general examination_ of the animal it is well, if the
examiner is not already acquainted with the history of the case (care, feed
and surroundings), to learn as much about this from the attendant as is
possible. Inquiry should be made as to the feeding, the conditions under
which the animal has been kept, the length of time it has been sick, its
actions, or any other information that may be of assistance in forming the
diagnosis and outlining the treatment.
The _general symptoms_ inform us regarding the condition of the different
groups of body organs. A careful study of this group of symptoms enables us
correctly to diagnose disease and inform ourselves as to the progress of
long, severe affections. These symptoms occur in connection with the pulse,
respirations, body temperature, skin and coat, visible mucous membranes,
secretions and excretions, and behavior of the animal.
_The local symptoms_ are confined to a definite part or organ. Swelling,
pain, tenderness and loss of function are common local symptoms. A _direct_
symptom may also be considered under this head because of its direct
relation to the seat of disease. It aids greatly in forming the diagnosis.
Other terms used in describing symptoms of disease are _objective_, which
includes all that can be recognized by the person making the examination;
_indirect_, which are observed at a distance from the seat of the disease;
and _premonitory_, which precede the direct, or characteristic symptoms.
The _subjective_ symptoms include such as are felt and described by the
patient. These symptoms are available from the human patient only.
Pulse.--The character of the intermittent expansion of the arteries, called
the pulse, informs us as to the condition of the heart and blood-vessels.
The frequency of the pulse beat varies in the different species of animals.
The smaller the animal the more frequent the pulse. In young animals the
number of beats per minute is greater than in adults. Excitement or fear,
especially if the animal possesses a nervous temperament, increases the
frequency of the pulse. During, and for a short time after, feeding and
exercise, the pulse rate is higher than when the animal is standing at
rest.
The following table gives the normal rate of the pulse beats per minute:
Horse 36 to 40 per minute
Ox 45 to 50 per minute
Sheep 70 to 80 per minute
Pig 70 to 80 per minute
Dog 90 to 100 per minute
In sickness the pulse is instantly responsive. It is of the greatest aid
in diagnosing and in noting the progress of the disease. The following
varieties of pulse may be mentioned: _frequent, infrequent, quick, slow,
large, small, hard, soft_ and _intermittent_. The terms frequent and
infrequent refer to the number of pulse beats in a given time; quick and
slow to the length of time required for the pulse wave to pass beneath the
finger; large and small to the volume of the wave; hard and soft to its
compressibility; and intermittent to the occasional missing of a beat. A
pulse beat that is small and quick, or large and soft, is frequently met
with in diseases of a serious character.
[Illustration: FIG. 3.--The X on the lower border of the jaw indicates the
place where the pulse is taken.]
_The horse's pulse_ is taken from the submaxillary artery at a point
anterior to, or below the angle of the jaw and along its inferior border
(Fig. 3). It is here that the artery winds around the inferior border of
the jaw in an upward direction, and, because of its location immediately
beneath the skin, it can be readily located by pressing lightly over the
region with the fingers.
_Cattle's pulse_ is taken from the same artery as in the horse. The artery
is most superficial a little above the border of the jaw. It is more
difficult to find the pulse wave in cattle than it is in horses, because of
the larger amount of connective tissue just beneath the skin and the
heavier muscles of the jaw. A very satisfactory pulse may be found in the
small arteries located along the inferior part of the lateral region of the
tail and near its base.
_The sheep's pulse_ may be taken directly from the femoral artery by
placing the fingers over the inner region of the thigh. By pressing with
the hand over the region of the heart we may determine its condition.
_The hog's pulse_ can easily be taken from the femoral artery on the
internal region of the thigh. The artery crosses this region obliquely and
is quite superficial toward its anterior and lower portion.
_The dog's_ pulse is usually taken from the brachial artery. The pulse wave
can be readily felt by resting the fingers over the inner region of the arm
and just above the elbow. The character of the heart beats in dogs may be
determined by resting the hand on the chest wall.
RESPIRATION.--The frequency of the respirations varies with the species.
The following table gives the frequency of the respirations in domestic
animals:
Horse 8 to 10 per minute
Ox 12 to 15 per minute
Sheep 12 to 20 per minute
Dog 15 to 20 per minute
Pig 10 to 15 per minute
The ratio of the heart beats to the respirations is about 1:4 or 1:5. This
ratio is not constant in ruminants. Rumination, muscular exertion and
excitement increase the frequency and cause the respirations to become
irregular. In disease the ratio between the heart beats and respirations
is greatly disturbed, and the character of the respiratory sounds and
movements may be greatly changed (Fig. 4).
[Illustration: FIG. 4.--Auscultation of the lungs can be practised to an
advantage over the outlined portion of the chest wall, only.]
Severe exercise and diseased conditions of the lungs cause the animal to
breathe rapidly and bring into use all of the respiratory muscles. Such
forced or labored breathing is a common symptom in serious lung diseases,
"bloat" in cattle, or any condition that may cause dyspnoea. Horses
affected with "heaves" show a double contraction of the muscles in the
region of the flank during expiration. In spasm of the diaphragm or
"thumps" the expiration appears to be a short, jerking movement of the
flank. In the abdominal form of respiration the movements of the walls of
the chest are limited. This occurs in pleurisy. In the thoracic form of
respiration the abdominal wall is held rigid and the movement of the chest
walls make up for the deficiency. This latter condition occurs in
peritonitis.
_A cough_ is caused by irritation of the membrane lining the air passages.
The character of the cough may vary according to the nature of the disease.
We may speak of a moist cough when the secretions in the air passages are
more or less abundant. A dry cough occurs when the lining membrane of the
air passages is dry and inflamed. This may occur in the early stage of the
inflammation, or as a result of irritation from dust or irritating gases.
Chronic cough occurs when the disease is of long duration or chronic. In
pleurisy the cough may be short and painful, and in broken wind, deep and
suppressed. In parasitic diseases of the air passages and lungs, the
paroxysm of coughing may be severe and "husky" in character.
The odor of the expired air, the character of the discharge and the
respiratory sounds found on making a careful examination are important aids
in arriving at a correct diagnosis, and in studying the progress of the
disease.
[Illustration: FIG. 5.--Fever thermometer.]
Body Temperature.--The body temperature of an animal is taken by inserting
the fever thermometer into the rectum. In large animals a five-inch, and in
small animals a four-inch fever thermometer is used. It should be inserted
full length and left in position from one and one-half to three minutes,
depending on the rapidity with which it registers (Fig. 5).
The average normal body temperatures of domestic animals are as follows:
Horses 100.5\260 F.
Cattle 101.4\260 F.
Sheep 104.0\260 F.
Swine 103.0\260 F.
Dog 101.4\260 F.
There is a wide variation in the body temperatures of domestic
animals. This is especially true of cattle, sheep and hogs. In order to
determine the normal temperature of an animal, it may be necessary to take
two or more readings at different times, and compare them with the body
temperatures of other animals in the herd that are known to be healthy.
Exercise, feeding, rumination, excitement, warm, close stables, exposure to
cold and drinking ice cold water are common causes of variations in the
body temperatures of domestic animals.
Visible Mucous Membranes.--The visible mucous membranes, as they are
termed, are the lining membranes of the eyelids, nostrils and nasal
cavities, and mouth. In health they are usually a pale red, excepting when
the animal is exercised or excited, when they appear a brighter red and
somewhat vascular. In disease the following changes in color and appearance
may be noted: When inflamed, as in cold in the head, a deep red; in
impoverished or bloodless conditions of the body and in internal
haemorrhage, pale; in diseases of the liver, sometimes yellowish, or dark
red; in diseases of the digestive tract (buccal mucous membrane), coated;
if inflamed, dry at first, later excessively moist; and in certain germ
diseases a mottled red, or showing nodules, ulcers and scars.
Surface of the Body.--When a horse is in a good condition and well cared
for, the coat is short, fine, glossy and smooth and the skin pliable and
elastic. Healthy cattle have a smooth, glossy coat and the skin feels
mellow and elastic. The fleece of sheep should appear smooth and have
plenty of yolk, the skin pliable and light pink in color. When the coat
loses its lustre and gloss and the skin becomes hard, rigid, thickened and
dirty, it indicates a lack of nutrition and an unhealthy condition of the
body. In sheep, during sickness, the wool may become dry and brittle and
the skin pale and rigid. When affected with external parasites, the hair or
wool becomes dirty and rough, a part of the skin may be denuded of hair,
and it appears thickened, leathery and scabby, or shows pimples, vesicles
and sores.
During fever, the temperature of the surface of the body is very unequal.
In serious diseases or diseases that are about to terminate fatally, the
skin feels cold and the hair is wet with sweat.
When animals are allowed to "rough it" during the cold weather, the coat of
hair becomes heavy and rough. This is a provision of nature and enables
them, as long as the coat is dry, to withstand severe cold.
Horses that are in a low physical condition, or when accustomed to hard
work, if then kept in a stall for a few days without exercise, commonly
show a filling of the cannon regions of the posterior extremities. This
condition also commonly occurs in disease and in mares that have reached
the latter period of pregnancy. Sheep that are unthrifty and in a poor
physical condition, especially if this is due to internal parasites,
frequently develop dropsical swellings in the region of the jaw, or neck.
Body Excretions.--The character of the body excretions, faeces and urine
may become greatly changed in certain diseases. It is important that the
stockman or veterinarian observe these changes, and in certain diseases
make an analysis of the urine. This may be necessary in order properly to
diagnose the case.
Behavior of the Animal.--When the body temperature is high, the animal may
appear greatly depressed. If suffering severe pain, it may be restless. In
diseases of the nervous system, the behavior of the animal may be greatly
changed. Spasms, convulsions, general local paralysis, stupid condition and
unconsciousness may occur as symptoms of this class of disease.
QUESTIONS
1. What information is necessary in order to be able to recognize or
diagnose disease? 2. What are the general symptoms of disease?
3. What are the subjective symptoms of disease?
4. Describe method of taking the pulse beat in the different animals and
its character in health and disease.
5. Give the ratio of the heart beats to the respirations in the different
species of animals.
6. What are the normal body temperatures in the different domestic animals?
7. What are the visible mucous membranes?
8. Is the condition of the coat and skin any help in the recognition of
disease?
CHAPTER III
TREATMENT
Preventive Treatment.--The subject of preventive medicine becomes more
important as our knowledge of the cause of disease advances. A knowledge of
feeds, methods of feeding, care, sanitation and the use of such biological
products as bacterins, vaccines and protective serums is of the greatest
importance to the farmer and veterinarian. We are beginning to realize that
one of the most important secrets of profitable and successful stock
raising is the prevention of disease; that the agricultural colleges are
doing a great work in helping to teach farmers that there are right and
wrong methods of feeding and caring for animals; that the practice of
sanitation in caring for animals is the cheapest method of treating
disease; and that it is advisable to practise radical methods of control,
when necessary, in order to rid the herd of an infectious disease.
_The ration fed_ and the method of feeding are not only important in
considering the causes of diseases of the digestive tract, but diseases of
other organs as well. The feeding of an excessive, or insufficient quantity
of feed, or a ration that is too concentrated, bulky and innutritious, poor
in quality, or spoiled may produce disease.
_An impure water supply_ is a common cause of disease. A deep well that is
closed in properly and does not permit of contamination from filth, does
not insure a clean water supply if the trough or tank is not kept clean.
_Farm Buildings_.--If stockmen would make a more careful study of the kind
of farm buildings most suitable to their needs, the selection of the
location, the proportions, the arrangement of the interior and the lighting
and ventilation, there would be a great saving in losses from disease, and
the cost of building in many cases would be lessened. Your neighbor's
building that you have taken for your model may not be suitable for your
needs. It may be more expensive than your financial condition permits. It
may be poorly lighted and ventilated and not suited to the site that you
have selected.
_Biological Products_.--There are a number of biological products that may
be used in the prevention and control of disease. Some of these products,
such as tuberculin and malein, enable the owner to rid his herds of
tubercular cows and glandered horses before these diseases have become far
enough advanced to be recognized by the visible symptoms alone. Black leg,
anthrax and hog-cholera vaccines are valuable agents in the control of
disease. In the treatment of fistula and infectious abortion, bacterins may
be used. There are many other germ diseases and infections for which
vaccines and bacterins may be used. However, we must not depend wholly on
these agents in the control of disease. We must possess a knowledge of the
manner in which the infection is spread, for without this knowledge we
would be unable to prevent its dissemination over a wide area.
Medicinal Treatment.--The average stockman or veterinarian is more familiar
with the treatment of disease with drugs than he is with the preventive
measures just described. This statement does not imply that a knowledge of
medicinal therapeutics is not of the greatest importance in the treatment
of disease. The ultimate object of all drugs is both to prevent and cure
disease, but the injudicious use of a drug does neither. A discussion of
this subject cannot be entered into here, and because of its largeness it
is not advisable to discuss it further than a brief summary of the methods
of administering drugs.
Administration of Drugs.--Drugs may be administered by the following
channels: by way of the mouth, in the feed or as a drench; by injecting
into the tissues beneath the skin or hypodermically; by rubbing into the
skin; by the air passages and the lungs; and by injecting into the rectum.
If the animal is not too sick to eat and the drug does not possess an
unpleasant taste, it may be given with the feed. If soluble, it may be
given with the drinking water, or in any case, it may be mixed with ground
feed if this method is to be preferred. In all cases the medicine must be
well mixed with the feed. This is especially important if there are a
number of animals to be treated, as there is more certainty of each animal
getting the proper dose and the danger of overdosing is avoided. If the
young animal is nursing the mother, we can take advantage of certain drugs
being eliminated in the mother's milk and administer the drug to the
mother.
[Illustration: FIG. 6.--A good kind of a dose syringe.]
DRENCHES.--In the larger animals a bulky drench is sometimes difficult to
administer, and we should, in all cases, count on a portion being wasted.
_Horses_ are sometimes difficult to drench, and it may be advisable to
confine the horse in some way. Small drenches can readily be given with a
syringe (Fig. 6) or a small bottle. In giving bulky drenches it is most
convenient to use a long-necked, heavy glass bottle. The horse should be
backed into a narrow stall and the head elevated by placing a loop in the
end of a small rope over the upper jaw, passing the rope back of the nose
piece on the halter and throwing it over a beam, and raising the head until
the mouth is slightly higher than the throat. If the horse refuses to
swallow, a tablespoonful of clean water may be dropped into the nostril.
This forces it to swallow. A drench should never be given through the nose,
as it may pass into the air passages and cause a fatal inflammation of the
lungs.
_Cattle_ can be easily drenched by taking hold of the nostrils with the
fingers, or snapping a bull ring into the partition between the nostrils
and elevating the head.
_Sheep_ may be drenched either in the standing position, or when thrown on
the haunches and held between the knees. Care should be exercised in giving
irritating drenches to sheep, especially if the drench be bulky.
_A herd of hogs_ may be quickly and easily drenched if they are confined in
a small pen, and the loop of a small rope placed around the snout, well
back toward the corners of the mouth. A small metal dose syringe should be
used. If the drench is bulky and the hog difficult to hold, it may be
necessary to elevate the head and raise the forefeet from the ground. The
drench should not be given until the hog is quiet and well under control,
as there is some danger of the medicine passing into the air passages and
doing harm. It may be necessary to mark the hogs that have been drenched
with a daub of paint, or in some other manner in order to be able to
distinguish them from the untreated animals.
The administration of drugs enclosed in a gelatin capsule, or mixing them
with syrup, honey or linseed oil, and rolling the mass into the form of a
cylinder is commonly practised. The _capsule_ or _ball_ may then be shot
into the pharynx with a balling gun. A ball may also be given to the larger
animals by carrying it into the back part of the mouth with the hand, and
placing it on the back part of the tongue. In the horse this method of
administration requires some practice. The tongue must be pulled well
forward, the head held up, and the tongue released as soon as the ball is
placed on the tongue, so that it may pass back into the pharynx.
The administration of drugs by _injecting beneath the skin_ (Fig. 7) is
suitable when the drug is non-irritating and the dose is small. Drugs
administered in this way act promptly and energetically. The alkaloid or
active principle of the drug is commonly used. A fold of the skin is picked
up with the fingers and the needle is quickly introduced, care being taken
not to prick or scratch the muscular tissue, as this causes some pain and
makes the animal restless. In order to avoid abscess formation at the point
of injection, the skin should be cleansed with a disinfectant and the
syringe and needle sterilized before using.
[Illustration: FIG. 7.--Hypodermic syringes.]
Drugs are not absorbed through the unbroken skin, but when applied with
friction, or when the outer layer is removed by blistering, absorption may
take place. Liniments, blisters and _poultices_ are the preparations used.
_Volatile drugs_, such as chloroform and ether, are absorbed quickly by the
enormous vascular surface of the lungs. This class of drugs is administered
for the purpose of producing general anaesthesia. _Anaesthetics_ are
indispensable in many surgical operations.
The administration of a drug in the form of _medicated steam_ is quite
useful in combating some respiratory diseases. In steaming large animals a
pail about half full of boiling-hot water to which has been added about an
ounce of coal-tar disinfectant, or whatever drug is required, is held
within about one foot of the animal's nostrils. It is usually advisable to
throw a light cover over the head and pail in order to direct the steam
toward the nostrils. Dogs can be placed on a cane-seated chair and a pail
or pan of boiling-hot water placed under it, and a sheet thrown over all.
Drugs are administered by way of the rectum when the animal can not be
drenched, or the drug can not be given in any other way and when a local
action is desired. An _enema_ or _clyster_ is a fluid injection into the
rectum and is employed for the following purposes: to accelerate the action
of a purgative; to stimulate the peristaltic movement of the intestines; to
kill intestinal parasites; to reduce body temperature; to administer
medicine; and to supply the animal with food. An enema may be administered
by allowing water to gravitate into the rectum from a height of two or
three feet or by using an injection pump. In the larger animals several
feet of heavy walled rubber tubing carrying a straight nozzle at one end
should be used. In administering an enema, the rectum should be emptied out
with the hand and the nozzle of the syringe carried as far forward as
possible. The operator should be careful not to irritate or tear the wall
of the rectum.
Size of the Dose.--The doses recommended in the treatment of the different
diseases, unless otherwise stated, are for mature animals. The dose for a
colt one year of age is about one-third the quantity given the adult, two
years of age one-half, and three years of age two-thirds. In well-matured
colts a larger dose may be given. In cattle, the doses recommended are
about the same. In the smaller animals the size of the dose may be based on
the development and age of the animal. When the drug is administered at
short intervals or repeated, the size of the dose should be reduced. The
physiological action of some drugs may be changed by varying the size of
the dose.
QUESTIONS
1. Give a general description of preventive treatment.
2. By what channels may drugs be administered?
3. How are drenches administered?
4. How are solid drugs administered?
5. What kind of drugs are administered hypodermically?
6. What is an enema?
7. What proportion of the dose of a drug recommended for the adult may be
given to immature animals?
PART II.--NON-SPECIFIC OR GENERAL DISEASES