Text printed in small capitals, bold face or italics are represented
here as ALL CAPITALS, between =equal signs= and between _underscores_,
respectively.
More Transcriber’s Notes may be found at the end of this text.
FARM LIFE SERIES
THE FARMER’S VETERINARIAN
By CHARLES WILLIAM BURKETT
HANDY FARM DEVICES AND HOW TO MAKE THEM
By ROLFE COBLEIGH
MAKING HORTICULTURE PAY
By M. G. KAINS
FARM CROPS
By CHARLES WILLIAM BURKETT
PROFITABLE STOCK RAISING
By CLARENCE A. SHAMEL
PROFITABLE POULTRY PRODUCTION
By M. G. KAINS
_Other Volumes in Preparation_
[Illustration: HEALTH]
The Farmer’s
Veterinarian
=A Practical Treatise on the Diseases of Farm Stock:= Containing Brief
and Popular Advice on the Nature, Cause and Treatment of Disease, the
Common Ailments and the Care and Management of Stock when Sick
_By_
CHARLES WILLIAM BURKETT
_Editor of American Agriculturist_
ILLUSTRATED
NEW YORK
ORANGE JUDD COMPANY
1914
_Copyright, 1909_
ORANGE JUDD COMPANY
NEW YORK
PRINTED IN U. S. A.
PREFACE
A large class of people, by force of circumstances, are compelled to
treat their own animals when sick or disabled. Qualified veterinarians
are not always available; and all the ills and accidents incident to
farm animals do not require professional attendance. Furthermore, the
skilled stockman should be familiar with common diseases and the
treatment of them. He should remember, too, that the maintenance of
health and vigor in our farm stock is the direct result of well-directed
management. Too frequently this is neither understood nor admitted, and
an unreasonable lack of attention, when animals are ill or indisposed,
works out dire mischief in the presence of physical disorder and
infectious diseases. A fair acquaintance with the common ailments is
helpful to the owner and to his stock. This leads to health, to
prevention of disease, and to skill in attendance when disease is at
hand.
The volume herewith presented abounds in helpful suggestions and
valuable information for the most successful treatment of ills and
accidents and disease troubles. It is an everyday handbook of disease
and its treatment, and contains the best ideas gathered from the various
authorities and the experience of a score of practical veterinarians in
all phases of veterinary practice.
C. W. BURKETT.
NEW YORK, June, 1909.
Table of Contents
Page
INTRODUCTION
Facing Disease on the Farm 1
CHAPTER I.
How the Animal Body is Formed 9
CHAPTER II.
Some Physiology You Ought to Know 21
CHAPTER III.
The Teeth as an Indication of Age 34
CHAPTER IV.
Examining Animals for Soundness and Health 39
CHAPTER V.
Wounds and Their Treatment 54
CHAPTER VI.
Making a Post-Mortem Examination 62
CHAPTER VII.
Common Medicines and Their Actions 69
CHAPTER VIII.
Meaning of Disease 82
CHAPTER IX.
Diagnosis and Treatment of Disease 92
CHAPTER X.
Diseases of Farm Animals 101
LIST OF ILLUSTRATIONS
Page
1. Health Frontispiece
2. Common Sheep Scab 3
3. Hog House and Feeding Floor 5
4. Poulticing the Throat 8
5. How a Cell Divides 10
6. Bones of Skeleton of a Horse 16
7. One of the Parasites of the Hog 18
8. Circulation and Digestion 22
9. Diseased Kidney 25
10. Stomach of Ruminant 27
11. Circulation of Blood in Body 30
12. Lumpy Jaw (jaw bone) 36
13. Bad Attitude Due to Conformation 41
14. Ewe Neck 46
15. Anatomy of the Foot 49
16. Fractures 54
17. Bandaging a Leg 57
18. Rickets in Pigs 63
19. Round Worms in Hog Intestines 66
20. Tetanus Bacilli 71
21. Ready for the Drench 81
22. Bacteria As Seen Under the Microscope 85
23. Result of Bone Spavin 90
24. Feeling the Pulse 94
25. How Heat Affects Growth 96
26. Diseases of the Horse 102
27. Lumpy Jaw (external view) 105
28. Where to Tap in Bloating 118
29. Bog Spavin 122
30. Horse Bots in Stomach 124
31. Colic Pains 138
32. Retention of the Urine 141
33. Curb 145
34. Fistulous Withers 156
35. Foot Rot in Sheep 160
36. Founder 163
37. Bad Case of Glanders 170
38. Ventral Hernia 180
39. An Attack of Cholera 182
40. The Result of Hog Cholera 186
41. Kidney Worms in the Hog 205
42. Liver Fluke 207
43. Lockjaw 209
44. Lymphangitis 215
45. Natural Presentation of the Foal 225
46. Abnormal Presentation of the Foal 227
47. Quittor 235
48. A Cattle Bath Tub 241
49. Side Bones 244
50. Splint 248
51. Twisted Stomach Worms 252
52. Tuberculosis Germs 264
Health and Disease Plate 1
Making Post Mortem Examinations Plate 2
A Victim of Tuberculosis Plate 3
Exterior Points of the Horse; Castration Plate 4
Texas Fever Plate 5
A Typical Case of Foot and Mouth Disease Plate 6
INTRODUCTION
Facing Disease on the Farm
To call a veterinarian or not--that is the question. Whether your horse
or cow is sick enough for professional attendance, or just under the
weather a little, is a problem you will always be called upon to face.
And you must meet it. It has always faced the man who raises stock, and
it is a problem that always will. Like human beings, farm stock have
their ailments and troubles; and, in most cases, a little care and
nursing are all that will be required. With these troubles all of us are
acquainted; especially those who have spent much time with the flocks
and the herds on the farm. Through experience we know that often with
every reasonable care, some animals, frequently the healthiest-looking
ones, in the field, or stable, give trouble at the most unsuspected
times. So the fault is not always with the owner.
There is no reason, however, why an effort should not be made, just as
soon as any trouble is noticed, to assist the sick animal to recover,
and help nature in every way possible to restore the invalid to its
usual normal condition. The average observing farmer, as a rule, knows
just about what the trouble is; he usually knows if treatment is beyond
him, and if not, what simple medical aid will be effective in bringing
about a recovery with greater dispatch than nature unaided will effect.
Now, of course, this means that the farmer should be acquainted with his
animals; in health and disease their actions should be familiar to him.
If he be a master of his business he naturally knows a great deal about
his farm stock. No man who grows corn or wheat ever raises either crop
extremely successfully unless he has an intimate knowledge of the soil,
the seed, the details of fertilization and culture. He has learned how
good soils look, how bad soils look; he knows if soils are healthy,
whether they are capable of producing big crops or little crops.
So with his stock. He must know, and he does know, something as to their
state of health or ill health. With steady observation his knowledge
will increase; and with experience he ought to be able to diagnose the
common ailments, and not only prescribe for their treatment, but
actually treat many of them himself. Unfortunately, many farmers pass
health along too lightly and the common disorders too seriously. This is
wrong. The man who deals with farm animals should be well acquainted
with them, just as the engineer is acquainted with his engine. If an
engine goes wrong the engineer endeavors to ascertain the trouble. If it
is beyond his experience and knowledge he turns the problem over to an
expert. It should be so with the stock raiser. So familiar should the
owner be with his animals in case of trouble he ought to know of some
helpful remedy or to know that the trouble is more serious than
ordinary, in which case the veterinarian should be called.
All of this means that the art of observing the simple functions should
be acquired at the earliest possible moment--where to find the pulse of
horse or cow, how many heart beats in a minute, how many respirations a
minute, the color of the healthy nostril, the use of the thermometer and
where to place it to get the information, the character of the eye, the
nature of the coat, the passage of dung and water, how the animal
swallows, the attitude when standing, the habit of lying down and
getting up--all of these should be as familiar to the true stockman as
the simplest details of tillage or of planting or of harvesting.
[Illustration: COMMON SHEEP SCAB
Here is an advanced case and shows how serious the trouble may become. A
very small itch mite is the cause. The mites live and multiply under the
scurf and scab of the skin.]
Moreover, the stockman should be a judge of external characters, whether
natural or temporary. He should have a knowledge of animal conformation.
If to know a good plow is desirable, then to know a good pastern or foot
is desirable. If the art of selecting wheat is a worthy acquisition,
then the art of comparing hocks of different horses is a worthy
accomplishment also. If experience tells the grower that his corn or
potatoes or cotton is strong, vigorous and healthy or just the reverse,
observation and experience ought also to tell him when his stock are in
good health or when they lack thrift or are sick and need treatment.
LEARN TO RECOGNIZE ANIMAL DISEASES
Few farmers there are, indeed, who are not acquainted with crop
diseases. Smut is readily recognized when present in the wheat or corn
or oat field; so colic, too, should be recognized when your horse is
affected by it. The peach and the apple have their common ailments; so
have the cow and pig. In either case the facts ought to be familiar. So
familiar that as soon as diagnosed and recognized prompt measures for
treatment should be followed that the cure may be effected before any
particular headway is at all made. Handled in this way, many cases that
are now passed on to the veterinarian would never develop into serious
disturbances at all.
PREVENTION BETTER THAN CURE
The old saying, “Prevention is better than cure,” is both wisdom and a
splendid platform on which to build any branch of live stock work. Every
disease is the result of some disturbance, somewhere. It may be improper
food; the stockman must know. Moldy fodder causes nervous troubles in
the horse. Cottonseed meal, if fed continuously to pigs, leads to their
death. Hence, food has much to do with health and disease. Ventilation
of the stable plays its part. Bad air leads to weakness, favors
tuberculosis, and, if not remedied, brings about loss and death. Fresh
air in abundance is better than medicine; and the careful stockman will
see that it be not denied.
Good sanitation, including cleanly quarters, wholesome water and dry
stables, has its reward in more healthy animals. When not provided, the
animals are frequently ill, or are in bad health more or less. As these
factors--proper food, good ventilation, and effective sanitation--are
introduced in stable accommodations, diseases will be lessened and stock
profits will increase.
[Illustration: HOG HOUSE AND FEEDING FLOOR
This convenient hog house is inexpensive, and the feeding floor at the
side insures cleanliness and thorough sanitary conditions. A sanitary
hog house should be one of the chief improvements of the farm.]
DISINFECT FREQUENTLY; IT NEVER HURTS AND IT MAY DO A WORLD OF GOOD
As disease is better understood it becomes more closely identified with
germs and bacteria. Hence, to lessen disease we must destroy, so far as
possible, the disease-producing germs. For this purpose nothing is
better than sunlight and disinfectants. Sunlight is itself death to all
germs; therefore, all stables, and the living quarters for farm animals,
should be light and airy, and free from damp corners and lodgment places
for dust, vermin, and bacteria. Even when animals are in good health,
disinfection is a splendid means for warding off disease. For sometimes
with the greatest care germs are admitted in some manner or form. By
constantly disinfecting, the likelihood of any encroachment by germs is
greatly lessened.
Fortunately we have disinfectants that are easily applied and easily
obtained at small cost. One of these disinfecting materials is lime,
just ordinary slaked lime, the lime that every farmer knows. While it
does not possess the disinfecting power of many other agents, it is,
nevertheless, very desirable for sprinkling about stables and for
whitewashing floors, walls, and partitions. When so used the cracks and
holes are filled and the germs destroyed. Ordinary farm stables should
be whitewashed once or twice each year, and the crumbled lime sprinkled
on the litter or open ground. It is not desirable to use lime with
bedding and manure, for the reason that it liberates the nitrogen
contained therein. Hence the bedding and manure should be removed to the
fields as frequently as possible, where it can be more helpful to the
land. Thus scattered, the sunlight and purifying effects of the soil
will soon destroy the disease bacteria, if any are present in the
manure.
Another splendid disinfectant is corrosive sublimate, mercuric chloride,
as it is often called. Use one ounce in eight gallons of water. This
makes one-tenth of one per cent solution. In preparing this
disinfectant, allow the material to stand for several hours, so as to
permit the chemical to become entirely dissolved. This solution should
be carefully guarded and protected, since it is a poison and, if drunk
by animals, is liable to cause death. If infected quarters are to be
disinfected, see that the loose dirt and litter is first removed before
applying the sublimate.
Carbolic acid is another satisfactory disinfectant. Usually a five per
cent solution is recommended. It can be easily applied to mangers,
stalls, and feed boxes. Enough should be applied so that the wood or
iron is made wet and the cracks and holes more or less filled. Chloride
of lime is a cheap and an easily prepared disinfectant. Use ten ounces
of chloride of lime to two gallons of water. This makes a four per cent
solution, and should be applied in the same way as the corrosive
sublimate.
Formalin has come into prominence very recently as a desirable
disinfectant. A five per cent solution fills the bill. Floors and cracks
should be made thoroughly wet with it. By using one or more of these
agents the living quarters of farm animals can be kept wholesome, sweet,
and free from germ diseases. In fact, the use of disinfectants is one of
the best aids of the farmer in warding off disease and in lessening its
effects when once present.
PUT SICK ANIMALS OFF BY THEMSELVES
Many diseases are introduced into a herd or flock by thoughtlessness on
the part of the owner. I have known distemper to be introduced into
stables and among horses, Texas fever and tuberculosis into herds of
cattle, and hog cholera among hogs, because diseased animals, when
purchased, were not separated off by themselves, for a short time at
least. If this were done, farmers would lessen the chance of an
introduction of disease into their healthy herds. Consequently
quarantine quarters should be provided; especially is this true if new
animals are frequently purchased and brought to the farm where many
animals are raised and handled. These quarantine quarters need not be
expensive, and they ought to be removed far enough from the farm stock
so that there may be no easy means of infection. When newly purchased
animals are placed in the quarantine quarters they should be kept there
long enough to determine if anything strange or unusual is taking place.
[Illustration: POULTICING THE THROAT
The picture shows how to apply a poultice to the throat.]
CHAPTER I
How the Animal Body is Formed
The cell is the unit of growth. It is so with all forms of life--plant
or animal, insect or bacterium. In the beginning the start is with a
single cell, an egg, if you please. After fertilization has taken place,
this single cell enlarges or grows. Many changes now occur, all rather
rapidly, until the cell walls become too small, when it breaks apart and
forms two cells just like the first used to be. This is known as cell
division. As growth increases, the number of cells increases also--until
in the end there are millions.
=Nature of the Cell.=--The cell is very small. In most cases it cannot
be seen with the naked eye. The microscope is necessary for a study of
the parts, the nature and the character of the cell.
In the first place the cell is a kind of inclosed sac, in which are
found the elements of growth and life. Surrounding the cell is a thin
wall known as the cell membrane. In plants this cell wall is composed of
cellulose, a woody substance, which is thin and tender in green and
growing plants, but hard and woody when the plant is mature.
Within the limits of the cell is the protoplasm, the chief constituent
of the cell; locked up in this protoplasm is life, the vital processes
that have to do with growth, development, individual existence.
Embedded within the protoplasm is another part known as the nucleus and
recognized under the microscope by its density. Around the nucleus is
centered the development of new cells or reproduction--for the changes
that convert the mother-cell into offspring-cells are first noted in
this place.
[Illustration: HOW A CELL DIVIDES
The simple steps in cell division are pictured here. Starting with a
single cell, growth and enlargement take place, ending finally in cell
division or the production of two individual cells.]
So much for plant cells. Is this principle different in animals? For a
long time it was thought that plants and animals were different. But
upon investigation it was discovered that animals were comprised of
cells just as plants. And not only was this discovered to be true, but
also that animal cells corresponded in all respects to plant cells.
Hence in animals are to be found cells possessing the cell walls formed
of a rather thick membrane, the granular protoplasm or yoke, and the
nucleus established in the yoke.
The ovum, known as the female egg, is composed of the parts just
described. If it is not fertilized when ripe it passes away and dies. If
fertilized in a natural way, it enlarges in size and subsequently
divides into two cells; and these, passing through similar changes,
finally give rise to the various groups of cells from which the body is
developed.
=The Animal Body a Group Collection.=--The body is, therefore, a mass of
cells; not all alike, of course, but grouped together for the purpose of
doing certain special kinds of work. In this way we have various groups,
with each group a community performing its own function. The brain forms
one community; and these cells are concerned with mind acts. The muscle
cells are busy in exerting force and action. Another group looks after
the secretions and digestive functions, while another group is concerned
solely with the function of generation and reproduction. And so it is
throughout the body.
Both individual cells and group cells are concerned with disease. One
cell may be diseased or destroyed, but the surrounding ones may go on
just the same. It is when the group is disturbed that the greatest
trouble results.
=A Word About the Cells.=--The cell always possesses its three
parts--membrane, protoplasm, and nucleus. But there is no rule as to the
size or shape. Cells may be round or oblong, any shape. Substances pass
in and out of the cell walls; and they are in motion, many of them,
especially those that line the intestines and the air passages, and the
white corpuscles of the blood. More than this, some cells, Dr.
Jekyl-like, change their appearance and shape, send out finger-like
bodies to catch enemies or food, and even travel all around in the
body, often leaving it altogether.
BODY TISSUES
The animal body contains five forms of tissues: Epithelial, in which the
cells are very compact, forming either thin or thick plates; the
connective tissue, by which many organs are supported or embedded;
muscle tissue, either smooth or striated, and in which the cells are in
fibers that contract and shorten; nerve-tissue, that has to do with
nerve and ganglion cells by which mental impulses are sent; and blood
and lymph tissue or fluid tissues.
The first group is intimately connected with the secretory organs, or
those organs which secrete certain substances essential for the proper
work of the body. Thus we have salivary glands, mucous glands, sweat
glands, and the liver and pancreas. Connective tissue includes fibrous
tissue, fatty tissue, cartilage and bone. The fibrous connective tissue
is illustrated when the skin is easily picked up in folds. Fatty tissue
occurs where large amounts of fat are deposited in the cells. Cartilage
is found where a large amount of firm support is required. With muscle
we are all familiar; it is the real lean meat of the body.
=Blood and Lymph.=--The blood is a fluid in which many cells are to be
found. The fluid is known as serum or blood-plasma and the cells as
corpuscles, and are both red and white. The red cells give the
characteristic color. When observed under a microscope, they appear as
small, round disks. They are of great importance to the body work.
Because of the coloring matter in them the oxygen of the air is
attracted when it comes in contact with the blood in the lungs. Oxygen
is in reality absorbed, and on the blood leaving the lungs it is
distributed to all parts of the body. The oxygen supply of the body is,
therefore, in the keeping of the red corpuscles.
White corpuscles have a different work; they guard the body by picking
up poison, bacteria, and other undesirable elements and cast these out
through the natural openings of the body. Compared with the red cells,
they exist in far less numbers and may wander about through all parts of
the body.
Lymph is a fluid in which a few cells, lymph corpuscles, are suspended.
These cells are very much like the colorless corpuscles of the blood,
only no red blood cells are present. But the lymph attends to its own
business; it bathes the tissues and endeavors to keep them in a healthy
condition.
=Skin and Hair.=--Without a covering the delicate muscles would be
unprotected. The skin serves in this capacity. It does still more; out
of it is exuded poisonous substances, perspiration, and, at the same
time, the skin is a sort of respiratory organ, through which much of the
carbonic acid formed in the body escapes.
The skin possesses two general layers, the cutis and sub-cutis; in the
first is contained also epidermis. Developed in the skin are the outer
coverings like hair, wool, feathers, horns, claws, and hoofs.
THE FRAMEWORK OF THE BODY
The framework of the body undergoes a gradual development from birth to
maturity. It represents the bony structure of the body; and on it all
other parts depend for support and protection. The brief summary of its
parts and work that follows here has been adapted from Wilcox and Smith.
=The Skeleton.=--This consists of a backbone, skull, shoulder girdle,
pelvic girdle, and two pairs of appendages. The backbone may be
conveniently divided into regions, each comprising a certain number of
vertebræ. The cervical vertebræ include those from the skull from the
first rib. In all mammals except the sloth and sea cow the number of
cervical vertebræ is seven, being long or short, according as the neck
of the animal is relatively long or short. The first and second cervical
vertebræ, known as the atlas and axis, are especially modified so as to
allow free turning movements of the head.
The next region includes the dorsal or thoracic vertebræ, which are
characterized by having ribs movably articulated with them. The number
is 13 in the cat, dog, ox, sheep, and goat; 14 in the hog; 18 or 19 in
the horse and ass, and six or seven in domestic poultry. In mammals they
are so joined together as to permit motion in several directions, but in
poultry the dorsal vertebræ are more rigidly articulated, those next to
the sacrum often being grown together with the sacrum. The spines are
high and much flattened in all ungulates, long and slender in dogs and
cats. They slope backward, forming strong points of attachment for the
back muscles. Several ribs, varying in number in different animals, meet
and become articulated with the breast bone or sternum. The sternum
consists of seven to nine articulated segments in our domestic mammals,
while in fowls the sternum is one thin high bone furnished with a keel
of varying depth. The lumbar vertebræ lie between the dorsal vertebræ
and the sacrum. The number is five in the horse, six in the hog, ox and
goat, and seven in the sheep. The sacrum is made up of a certain number
of vertebræ, which are rigidly united and serve as an articulation for
the pelvic arch. The number of sacral vertebræ is five in the ox and
horse, four in sheep and hogs, and 12 to 17 in birds. The caudal or tail
vertebræ naturally vary in number according to the length of the tail (7
to 10 in sheep, 21 in the ox, 23 in hogs, 17 in the horse, 22 in the
cat, 16 to 23 in the dog).
In ungulates the anterior ribs are scarcely curved, the chest being very
narrow in front. The number of pairs of ribs is the same as the number
of dorsal vertebræ with which they articulate.
=The Skull.=--This part of the skeleton is really composed of a number
of modified vertebræ, just how many is not determined. The difference in
the shape of the skulls of different animals is determined by the
relative size of the various bones of the skull. In hogs, for example,
the head has been much shortened as a result of breeding, thus giving
the skull of the improved breeds a very different appearance from that
of the razorback.
The shoulder girdle consists of a shoulder blade, collar bone and
coracoid on either side. The fore leg (or wing, in case of birds)
articulates with the socket formed by the junction of these three bones.
In all the ungulates the shoulder blade is high and narrow, the coracoid
is never much developed, and the collar bone is absent. In fowls all
three bones of the shoulder girdle are well developed, the collar bone
being represented by the “wish bone.”
=The Pelvic Girdle.=--This consists of three bones on either side, viz.,
ilium, ischium, and pubis. The first two are directly articulated to the
spinal column, while the pubic bones of either side unite below to
complete the arch. The three bones of each side of the pelvis are
present in all our domestic animals, including the fowls.
[Illustration: BONES OF THE SKELETON OF A HORSE
1 Face Bones, 2 Neck Bones or Cervical Vertebræ, 3 Scapula or Shoulder
Blade, 4 Humerus or Arm Bone, 5 Radius or Bone of Forearm, 6 Carpus or
Knee, 7 Shank Bone or Cannon, 8 Upper Pastern, 9 Lower Pastern,
10 Coffin Bone, 11 Ulna or Elbow, 12 Cartilages of the Rib, 13 Costæ or
Ribs, 14 Dorsal Vertebræ or Bones of Back, 15 Lumbar Vertebræ or Bones
of Loin, 16 Candal Vertebræ or Bones of Tail, 17 Haunch, 18 Femur or
Thigh Bone, 19 Stifle Joint, 20 Tibia, 21 Tarsus or Hock, 22 Metatarsal
Bones, 23 Upper Pastern Bone, 24 Lower Pastern Bone, 25 Coffin Bone.]
=Legbones of Farm Animals.=--There is one formula for the bones of the
fore and hind legs of farm animals. The first segment is a single bone,
the humerus of the fore leg, femur of the hind leg. In the next segment
there are two bones, radius and ulna in the fore leg, tibia and fibula
in the hind leg. In the dog, cat, and Belgian hare the radius and ulna
are both well developed and distinct. In ungulates the humerus is short
and stout, while the ulna is complete in the pig, rudimentary and behind
the radius in ruminants and firmly united with the radius in the horse.
Similarly with the hind leg the fibula is a complete bone in the pig,
while in the horse there is merely a rudiment of it, attached to the
tibia.
=Feet.=--The mammalian skeleton has undergone the greatest modification
in the bones of the feet. In the horse there are only six of the
original ten wrist or carpal bones, and, since there is but one of the
original five toes, the horse has also but one metacarpal or cannon
bone. Splint-like rudiments of two other metacarpal bones are to be
found at the upper end of the cannon bone, or at the “knee” joint. Below
the cannon bone, and forming the shaft of the foot, we have the small
cannon bone, coronary bone, and coffin bone--the last being within the
hoof with the navicular bone behind it. The stifle joint of the horse
corresponds to the knee of man. The “knee” of the horse’s fore leg
corresponds to the hock of the hind leg, both being at the upper end of
the cannon bone. The fetlock joint is between the large and small cannon
bones, the pastern joint between the small cannon or large pastern
bones, and the coffin joint between the coronary and coffin bones. The
horse walks upon what corresponds to the nail of the middle finger and
middle toe of man.
In pigs four digits touch the ground, the first being absent and the
third and fourth larger and in front of the second and fifth. In
ruminants the third and fourth digits reach the ground, while the second
and fifth do not. In dogs the first digit appears on the side of the
leg, not in contact with the ground.
[Illustration: ONE OF THE PARASITES OF THE HOG
The thorn-headed worm attached to the anterior part of the small
intestine often causes death. Not more than five or six are usually
found in a single animal.]
In fowls the wing, which corresponds to the fore leg of mammals, shows a
well-developed humerus, radius and ulna, while only one carpal and one
metacarpal bone remain, along which the wing feathers are attached. In
the leg the femur and tibia are strong bones, but the fibula is a mere
splint. The tarsal bones are absent, while the shank consists of a
metatarsal bone (really three bones fused together), to which the four
toes are articulated.
=The Muscular System of Farm Animals.=--The muscular system is too
elaborate, the number of muscles too great, and their modifications for
different purposes too complex for consideration in detail in the
present volume. All muscles are either striped or unstriped (as examined
under the microscope), according as they are under the immediate control
of the will or not. The heart muscle forms an exception, for it is
striped though involuntary. The essential characteristic of muscle
fibers is contractility, which they possess in high degree. The typical
striped muscles are concerned in locomotion, being attached at either
end to a bone and extending across some movable joint. The most
important unstriped muscles are found in the walls of the intestines and
blood vessels.
=The Nervous System.=--In so far as our present purposes are concerned,
the nervous system may be disposed of in a few words. The central
nervous system consists of a brain and spinal cord. The microscopic
elements of this tissue are peculiarly modified cells, consisting of a
central body, from which fibers run in two or more directions. The cell
bodies constitute the gray matter, and the fibers the white matter of
the brain and spinal cord. The gray substance is inside the spinal cord
and on the surface of the brain, constituting the cortex. The most
important parts of the brain are the cerebrum, optic lobes, cerebellum,
and medulla. There are twelve pairs of cranial nerves originating in the
brain and controlling the special senses, movements of the face,
respiration, and pulse rate. From each segment of the spinal cord a pair
of spinal nerves arises, each of which possess both sensory and motor
roots. The sympathetic nervous system consists of a trunk on either
side, running from the base of the skull to the pelvis, furnished with
ganglionic enlargements and connected with the spinal nerves by small
fibers.
=The Respiratory Organs.=--These include the nose, larynx, trachea or
windpipe, and lungs. The trachea forks into bronchi and bronchioles of
smaller and smaller size, ending in the alveoli or blind sacs of the
lungs. In fowls there are numerous extensions of the respiratory system
known as air sacs, and located in the body cavity and also in the hollow
bones. The air sacs communicate with the lungs, but not with one
another.
=The Urinary Organs.=--These consist of kidneys connecting by means of
ureters with a bladder from which the urethra conducts the urine to the
outside. In the male the urethra passes through the penis and in the
female it ends just above the opening of the vagina. The kidneys are
usually inclosed in a capsule of fat. The right kidney of the horse is
heart-shaped, the left bean-shaped. Each kidney of the ox shows 15 to 20
lobes, and is oval in form. The kidneys of sheep, goats, and swine are
bean-shaped and without lobes.
=The Reproductive Apparatus.=--This consists of ovaries, oviducts,
uterus or womb, and vagina in the female; the testes, spermatic cords,
seminal vesicle and penis, together with various connecting glands,
especially prostate gland and Cowper’s gland, in the male. In fowls
there is no urinary bladder, but the ureters open into the cloaca or
posterior part of the rectum. The vagina and uterus are also wanting in
fowls, the oviducts opening directly into the rectum. The male
copulating organ is absent except in ducks, geese, swan, and the
ostrich.