DIAGNOSIS AND PREVENTION OF TUBERCULOSIS. 
453 
a short time it becomes poorer in quality while it may increase 
in quantity. The external or superficial glands, in many in¬ 
stances, will decide the question of this malady. They are 
larger than normal, nodulated, and those on one side of the 
body will not correspond in size to the opposite. Tubercles are 
sometimes found in or under the skin, and are easily felt in the 
form of well-defined nodules. 
The placenta in tuberculous animals is often studded with 
small, opaque, well-defined new formations. The bones and 
articulations are not uncommonly attacked, those entering into 
the formation of the elbow, knee, hock and styfle joints being 
most often affected. Lameness is very often marked in some 
cases, the joints swollen and tense, the ends of the bones en¬ 
larged. The diseased bone may crumble, and sharp spiculse 
protrude through the skin. The cerebro spinal system is not 
exempt from its ravages, and tubercular meningitis is not in¬ 
frequent. The symptoms will vary according to the location, 
from excitement to stupor, paralysis, partial or complete. Some 
animals will walk in a circle for days with the head down and 
to one side. Young animals not infrequently die from acute 
tubercular meningitis. Paraplegia is seen when the lesions are 
located in the lumbar region of the spinal cord. It is generally 
acknowledged that the diagnosis of tuberculosis is no simple 
matter in any stage, especially where one cannot obtain a history 
of association with tuberculous animals; then how much more 
must it be in occult and equivocal cases. Instead of depending 
upon a physical examination or clinical observation to diagnose 
this malady, use can be made of the microscope, inoculation or 
the injection of tuberculin. 
The first two methods require special study and considerable 
time, which is not practical or desirable when a large number 
of animals are in question, while the third has been demon¬ 
strated to be an almost infallible test with proper care and 
observation. The tuberculin test is based on the fact, as shown by 
Koch, that it increases the activity of the disease process, creat- 
ing a general disturbance of the system, which is manifest by an 
