BOVINE TUBERCULOSIS. 265 
Both bovine and human tuberculosis are caused by a bacterium 
that has great similarity in the two animals. But there are slight 
differences between them, both in microscopic appearance and in 
methods of growth, sufficient to make it necessary to recognize them 
as somewhat different types. When inoculated into animals, the 
organism from the bovine source proves to be more virulent than 
the one from the human source. The human bacillus, when 
inoculated into cattle, generally produces only a slight trouble, 
while the bovine bacillus is apt to bring about a progressive case of 
the disease of very serious character. What effect the bovine 
bacillus has when inoculated into man cannot yet be told from 
direct experiment, but there appear to be a number of tolerably 
sure cases of accidental inoculation of human beings with the bovine 
bacillus that have been followed by a development of the disease. 
The general conclusion is that, although the two are slightly different, 
each may produce the disease in the other animal, and that the 
disease is, therefore, transmissible from animals to man. While the 
conclusion is still doubted by Prof. Koch, it is accepted by most 
other bacteriologists. Whether the bovine bacillus is more virulent 
for man than is the human bacillus, as it is for other animals, is by no 
means settled. Furthermore, it is pretty generally agreed that 
human tuberculosis comes more often from human sources than 
from cattle. 
BOVINE TUBERCULOSIS. 
In recent years, owing largely to the feeding of swine with 
creamery refuse, the disease is coming to be somewhat common 
among swine. But it is among cattle that the trouble is most 
widely distributed and of the most serious import. In cattle it 
attacks chiefly the glands of the neck, the glands of the intestinal 
tract, and the lungs. It may be located in the udder; and in these 
cases the milk of the animal becomes a source of danger. For- 
tunately, the percentage of cases of udder disease is comparatively 
small. In cattle it rarely attacks the bones, joints, or muscles. 
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