118 POULTRY DISEASES 



of the organisms grown for considerable time in 

 the various animals and some differences (bio- 

 chemically) when grown in artificial media after 

 isolation, yet the type peculiar to any of the warm- 

 blooded animals will grow in any of the other 

 warm-blooded animals, that is, the types are in- 

 terchangeable, which means that the bovine type 

 may cause tuberculosis in man and the human type 

 may cause tuberculosis in birds, etc. Most auth- 

 ors consider that while the chicken has consider- 

 able resistance to the human type, it will and does 

 become infected with this type. 



It has been found that a large percentage of 

 hogs fed swill from houses where tuberculous per- 

 sons have expectorated into it, become tubercul- 

 ous, and when slaughtered, there is a considerable 

 loss from condemnation of those badly affected. 

 (Busman.) 



Tuberculosis among chickens is rare in some 

 portions, and is very common in other localities in 

 the United States. Although it is widespread 

 throughout the United States and Canada, it was 

 first reported in this country in 1900 and received 

 but slight attention until 1903. It also occurs in 

 turkeys, pigeons and pheasants, and two eases 

 in wild geese were reported at the Ontario Agri- 

 cultural College. The loss from this disease seems 

 to be increasing. 



Mode of Spread. — In the progress of tuberculo- 

 sis of chickens at times there is noted a diarrhea. 

 In these cases there are found tubercular ulcers 

 of the mucous lining of the intestinal tract. In 

 these cases the spread is very rapid through the 

 flock, as birds . are continually picking feed from 

 the ground and floors where contamination is sure 

 to have taken place. 



