TUBBRCULOSIS. 165 



part in transmitting tuberculosis. It has been found that 

 cattle or other animals affected with tuberculosis more often 

 distribute the disease through feces from the intestinal tract 

 than in any other way. Even if the digestive tract should 

 not be the location or seat of the trouble, it acts as a carrier, 

 for, as is well known, ]>ut few animals do or can expectorate 

 from the mouth. If their lungs or respiratory tract are affected 

 with any disease, they cough the mucus into the mouth and 

 swallow it, and such amount of the bacilli as do not find 

 lodgment again are passed out to the ground, as digestive pro- 

 cesses have little or no effect upon them. In this manner they 

 are distributed to pigs and lower animals. Cows located in 

 the same envircmment become contaminated with the dirt and 

 filth upon their udders and coats of hair, and when the milk- 

 ing is done this in turn to a greater or less degree contami- 

 nates the milk, and hence we have the bacilli in the milk of 

 perfectly' healthy cows. We have seen large quantities of 

 milk strained in many dairies, but have not found the dairy 

 in which the milk was removed from the cows with a degree 

 of cleanliness so perfect that the cloth or screen through 

 which it was strained did not show the presence of some cattle 

 hairs and fragments of a substance suspiciously like feces. 



When we know how completely cattle feces may be charged 

 with tubercle bacilli and how easily milk ma}' be affected from 

 this source, and contemplate this fact, keeping in mind the 

 wide distribution that dairy products have, and add to our 

 knowledge some of the results obtained and published by 

 competent investigators, we must conclude that the eradica- 

 tion of tuberculosis amongst cattle cannot be too vigorously 

 urged or pursued. 



Numerous investigators have shown that pulmonary or 

 lung tuberculosis is the most common form of the disease in 

 animals, irrespective of the point at which the tubercular 

 infection enters the body, and that tubercle bacilli may pass 

 through the wall of the intestine and reach the lung without 

 visible disease of the intestinal mucosa. 



