STATE DAIRY ASSOCIATION. 



35J 



SUCCESS OF TUBERCULIN TEST. 



Fortunately we have an almost unerring method by which we can 

 detect the presence of tuberculosis in any animal whether or not the 

 disease is sufficiently advanced for the symptoms to become apparent 

 on an ordinary examination. This method is known as the tuberculin 

 test, which I shall describe briefly. A serum, known as tuberculin, made 

 from the culture of tubercle bacilH, is injected under the skin of the 

 animal to be tested, whereupon it is rapidly absorbed and carried into 

 the blood stream. If the animal injected is free from tuberculosis there is 

 no result whatever, from the injection. If the animal is diseased with 

 tuberculosis there will follow in from 9 to 16 hours after the injection, 

 a marked rise in the temperature. The rise in the temperature indicat- 

 ing tuberculosis should be the highest at about the 13th hour after the 

 injection, and should amount to as much as 3 degrees and often the 

 rise of 5 or 6 degrees. Such a rise following between the 9th and 

 1 6th hour after the injection of a cow with tuberculin indicates that the 

 animal is affected with tuberculosis. The temperature of cattle is some- 

 what irregular, and may be quite different in different individuals, so it 

 becomes necessary in making the test to take the temperature of the 

 animals to be tested two or three times before the injection is made 

 in order to be able to make a correct comparison with the temperatures 

 after injection. The following brief table shows the various tem- 

 peratures of two animals which I have tested : 



Each cow was injected with 2cc. or 30 drops of tuberculin at g. 

 o'clock p. m. March 11, 1905. 



ILLUSTRATIONS OF THE TEST. 



This table shows the temperatures of animals taken twice before 

 the injection and four times after beginning the loth hour after the 

 injection. The highest temperature of No. 148 before injection was 

 101.8, the highest temperature after the injection, 101.8, showing no 

 reaction whatever, so the animal was marked healthy. The highest 

 temperature of 245 before injection was 101.4 and after injection 106. 



These two instances fairly illustrate the results of the test of any 

 herd. Where there are no tuberculous animals in the herd, results- 



