Bovine Tubeucttlosis. 151 



they do not show evidence of tuberculosis for many years. I have 

 known of a very large percentage of calves fed upon milk of diseased 

 animals to give a good tuberculin reaction (thus showing the disease) 

 before they were six months old. This is believed by the writer to 

 be one of the very important ways by which the disease is disseminated 

 in breeding herds. 



Tuberculosis is often found in swine fed upon milk from infected 

 cows. In 1903 the writer knew of a carload of hogs that had been 

 purchased in a district where there were many tuberculous cows, and 

 of which the first 59 of them that were slaughtered were all tubercu- 

 lous. The remainder were not killed at that time. While such a 

 condition may be considered an exception, it is a fact that many 

 swine are infected, especially when they are fed tuberculous milk. 



Fig 33. — Liver of a cow showing two small tubercular deposits. They were the onhj 

 lesions found. The cow gave a typical tuberculin reaction. Natural size. 



Last year the United States meat inspectors condemned about 20,000 

 hogs for tuberculosis. 



It should be remembered that the greater the percentage of tuber- 

 culous cows in the herd, and the further advanced the disease is in 

 the cattle, the greater the danger of infection from the use of the 

 milk. In cases where the disease is restricted to small nodules in the 

 lymphatic glands, or perhaps in the lungs, the danger of tubercle 

 bacilli being in the milk is very slight, but when the udder is tuber- 

 culous they are constantly present in the milk and often in very large 

 numbers. When calves or pigs are fed with milk of this kind, they 

 are almost sure to be infected. The same result may follow when 

 it is fed to children or adults. 



