orterhouse cuts of
beef. The grapelike tuberculous growths are mainly restricted to the lining
membrane of the abdomen.

Fig. 2. Tuberculosis of the pleura of a cow, so-called "pearly disease."
Notice the grapelike clusters of tubercular nodules scattered over the
lining membrane of the chest (pleura).

PLATE XXXVIII. Tuberculosis of cow's udder. The udder was uniformly swollen
and quite firm. Small cheesy foci and yellowish lines of tuberculous
material follow the course of the milk ducts. The mucous membrane of the
milk cistern (_a_) is ulcerated and covered with yellowish cheesy
particles. The supramammary lymphatic gland (_b_) is greatly enlarged and
contains many miliary tubercular foci.

* * * * *

Tuberculosis in the abdominal organs is often signalized by abortion and by
abnormal sexual manifestations. When the brain is involved, the disease may
cause convulsions, unconsciousness, paralysis, as well as peculiar
movements in a circle, oblique position of the head, etc. Lydtin quotes the
following description of the disease as taken from a Swiss sanitary order:

A dry, short, interrupted, hoarse cough, which the sick animals
manifest, especially in the morning at feeding time, still more after
somewhat violent exertion. At first these animals may be full blooded
and lay on a considerable amount of fat when well fed. As the disease
progresses they grow thin and show more and more those appearances which
indicate diseased nutrition, such as a staring, lusterless, disheveled
coat; dirty, tense skin, which appears very pale in those regions free
from hair. The temperature of the skin is below normal. The loss of fat
causes sinking of the eyes in their sockets. They appear swimming in
water, and their expression is weak. The cough is more frequent, but
never or very rarely accompanied with discharge. The body continues to
emaciate, even with plenty of food and a good appetite, so that the
quantity of milk is small. At times in the early stages of the disease,
still more in the later stages, the diseased animals manifest
considerable tenderness when pressure is applied to the front or the
sides of the chest by coughing, moaning, etc. Often symptoms are wanting
in spite of the existence of the disease.

Lydtin also quotes at length a description of the abnormal sexual desire
occasionally observed among cows when affected with this disease.

_Diagnosis.