384 The Diseases of Animals 
bringing oxygen, carrying away the waste, and keeping 
the quarters dry. Sunlight, fresh air, dryness and 
cleanliness, with good food, are essentials in preserving 
a healthy herd. 
The Tuberculin Test 
The most accurate means of detecting tuberculosis 
in cattle is by injecting a small amount of “tuberculin” 
beneath the skin. If the animal has the disease, there 
follows, in about twelve hours, a rise of temperature 
or fever, which lasts for a few hours and then sub- 
sides. Tubereulin is a toxin excreted by the tubercle 
bacillus during the process of its growth. When 
prepared for use, tuberculin contains no germs of tuber- 
culosis, and is incapable of producing the disease. 
In testing animals with tuberculin the temperature 
of the tested subject is taken with a clinical (fever) 
thermometer every two hours, beginning at 6 A. M. 
and continuing until 12 P. M., when a small quantity of 
tuberculin is injected under the skin and the tempera- 
ture again taken as on the preceding day. If the 
animal has tuberculosis there is a rise of tempera- 
ture of two to six degrees Fahr. If the animal is free 
from the disease the temperature does not rise or vary 
more than the normal daily variation. Careful attention 
should be given to the manner in which the temperature 
rises. A sudden and rapid rise of temperature is to 
be regarded with suspicion. In a typical reaction to 
the tuberculin test, the temperature rises gradually for 
two hours or more until it attains its maximum; then 
