Tuberculosis 385 



it gradually subsides. While the testing by tuber- 

 culin is not a difficult task, it is usually economy to 

 employ some one who has had. some experience, and 

 who can give due consideration to the various in- 

 fluences that modify the reaction. Cattle should not 

 be tested too frequently with tuberculin, as the system 

 acquires a tolerance and does not respond accurately. 

 One test yearly, or not oftener than once in six months, 

 is usually efficient. 



In testing cattle, the animals should be disturbed as 

 little as possible. They should be given small quanti- 

 ties of water frequently, but not turned out and allowed 

 to drink large quantities, as this is liable to cause a 

 sudden fall of temperature. 



Tuberculin is not infallible. In some cases, espe- 

 cially when the animal is badly diseased, it fails to 

 cause a rise of temperature, and in a few cases it causes 

 a rise of temperature in healthy animals; but the per- 

 centage of the errors is very small, and at the present 

 time tuberculin is the most effective means known for 

 detecting tuberculosis in animals. The subcutaneous 

 injection of mallein seems to be the best method. 



After a herd has been tested and all tuberculous 

 animals have been removed, the barns and stables 

 should be thoroughly cleaned and disinfected before 

 other cattle are put in. No animals should be ad- 

 mitted to a healthy herd until they have been tested 

 and found to be free from this disease. 



In Denmark, the following plan for eradication of 

 tuberculosis, called the Bang method, has been tried with 

 success. All cattle are tested with tuberculin, and tiiose 



