DR. LEGEAR'S STOCK BOOK. 315 



BOVINE TUBERCULOSIS, OR ANIMAL CONSUMPTION. 



In speaking of consumption, it is generally understood to 

 mean a disease of the human family characterized by an affection 

 or "wasting a\vay" of the lungs. But we may have consumption 

 of other organs of the body as well, and so are the lower animals 

 subject to this same disease. 



We are not sure of the exact time that this disease made its 

 first appearance, but it has been known for many centuries, and 

 legislative enactments having reference to the destruction of af- 

 fected animals and forbidding the use of the flesh date far back 

 into the Middle Ages. 



Nature and Cause. All kinds of theories prevailed as to the 

 nature and cause of consumption until Robert Koch, in 1882, 

 proved it to be a disease due to a germ (bacillus tuberculosis) 

 and that this germ caused the disease in all the lower animals 

 and in man. This wonderful discovery at once put an end to all 

 disputes and controversies as to it causation. The germ is a 

 slender, rod-like body, so small that it can not be seen with the 

 naked eye. When it has become lodged in any organ or tissue 

 it begins to multiply, setting up an irritation which leads to the 

 formation of little nodules or tubercles; these, when full grown, 

 arc about the size of a millet seed. When these tubercles con- 

 tinue to form in large numbers they run together, forming 

 masses of various sizes. 



There are several ways in which these germs may find their 

 way into the body: First, by inhalation into the lungs; second, 

 into the digestive tract in the milk of consumptive cows. Other 

 ways could he given, but. the two named are the most common 

 modes of infection. 



It has hern shown by thousands of experiments that the dis- 

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