Common Diseases of Farm Animals | Page 4

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