232 POULTRY CULTURE 



disease while baby chicks and sell these birds or at least keep 

 them separate from those not suffering an attack. Breed 

 only from those not affected while baby chicks. 



TUBERCULOSIS 



Tuberculosis is a disease that destroys one-tenth of the 

 human population. Often persons become infected from the 

 lower animals. Thus, the milk and meat from a cow suffering 

 from tuberculosis. Likewise, pork from a hog suffering from 

 tuberculosis may be dangerous. Likewise, a bird suffering 

 from the disease should not be used for food. 



In some locahties in the United States tuberculosis in birds 

 is rather common and is a serious menace. 



In 1882 Koch, a German physician, discovered the germ of 

 tuberculosis. It is a slender, rod-shaped organism, requiring 

 special staining, and cannot be seen except by aid of the micro- 

 scope. Chickens may become infected by being placed in 

 quarters where infected birds have been kept or by having an 

 infected bird introduced into the flock. 



Care should be exercised not to allow any birds from an in- 

 fected flock to be sold, as that is a means of the spread of the 

 disease. 



The flock should be destroyed, the premises should be thor- 

 oughly cleaned, and the building disinfected in a thorough 

 manner. Whether the disease is eradicated from infected 

 quarters will depend on how thorough the work of cleaning 

 and disinfection is carried out. 



Symptoms. — ^No absolute diagnosis can be made during life 

 from the physical signs or symptoms. Recently a test has 

 been made by using tuberculin similar to that used in cattle, 

 except that the tuberculin is made from a culture of the avian 

 or chicken variety of the Bacillus tuberculosis. This tuber- 

 culin is injected into the skin on the surface of the comb or 

 wattles, and if the bird is suffering with the disease a swelhng 

 wiU appear in twenty-four to seventy-two hours. This is the 

 intradermal method of diagnosing tuberculosis, and was first 

 used successfully in testing cattle for tuberculosis. Van Es 

 and his co-workers first used it on birds. 



