748 GENERAL THERAPEUTIC' MEASURES 



The Test. — It is best to take the temperature of the animal 

 from 6 A.M. every two hours until the tuberculin is injected on 

 the evening of the same day between 8 and 10 o'clock. The test 

 is unreliable in animals whose temperature reaches 103° P. (ex- 

 cept in the young, when this may be considered a normal, maxi- 

 mum temperature) during this period prior to the injection, and 

 sometimes in those in advanced stages of the disease. The test 

 is also misleading within a few days of parturition, either before 

 or after. The injection is made aseptically into the subcutaneous 

 tissue in the side of the neck or back of the left scapula with a 

 syringe and needle previously boiled. The animals should be 

 kept in the stable during the time required for the test, and 

 should not be allowed to drink large quantities of cold water to 

 reduce their temperature while the test is being made. The 

 temperature of the animal should be taken at 6 o'clock on the 

 niorning following the injection and from that time every two 

 hours till 8 P.M. 



A rise of two degrees F. is necessary for a positive reaction ; 

 that is, a rise of two degrees over the maximum temperature of 

 the animal in the fourteen to sixteen hours before the injection. 

 Those animals in which the temperature does not rise to 103° F. 

 within fifteen or at most twenty hours after injection may be 

 considered non-tuberculous; when the temperature is between 

 103° and 104° F. the test is doubtful, and the animals should 

 be re-tested after two months; when the temperature rises grad- 

 ually to 104° F. or over within fifteen hours after the injection, 

 the animals may be classed positively tuberculous, provided the 

 temperature constitutes a rise of two degrees over the maximum 

 temperature recorded prior to the injection. Before admitting 

 new cows to a herd they should be isolated until tested twice 

 with tuberculin without reacting. This is necessary because 

 cows may not react in the incubative or latent stage and because 

 previous injection of tuberculous cows with tuberculin may pre- 

 vent them from reacting to small doses. Therefore after a first 

 test with negative result the cows are kept isolated for three 

 months, when a second test is made with three times the first dose 

 of tuberculin. Milk from these cows may be sold as certified 

 milk during the isolation period. 



Animals should be kept at rest before the tuberculin test is 

 made. Tasteless antipyretics are sometimes put in food to 

 prevent the action of tuberculin. 



The average dose of tuberculin as prepared and diluted for 

 immediate use by the U. S. Government is 2 c.c, representing 



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