Tuberculosis. 121 



The mercury should always be shaken down below 98 

 F. before the thermometer is inserted. If the animal 

 objects to the insertion, scratching her back with a card 

 will attract her attention and no difficulty be met. 

 Vaseline may be used on the instrument to aid in its 

 insertion. 



The temperature should be taken four times at inter- 

 vals of. 2 hours, before the injection of the tuberculin. 

 The injection of the tuberculin is made by the use of a 

 well-made hypodermic syringe. The injection is made 

 usually back of the shoulder blade, but may be made 

 wherever the skin is loose and thin. The needle is 

 thrust through the skin at right angles, but care should 

 be taken not to push it into the muscular tissue below. 

 A syringe with a needle that slips on, rather than one 

 that screws on to the barrel is preferable, since the 

 needle can be inserted and the syringe then attached. 

 The needle should be of 15 or 17 wire guage; strong 

 needles are needed for this kind of work. It is well to 

 sterilize the syringe before using by placing it in a pan 

 of cold water and bringing the water to a boil. 



Animals whose temperatures are abnormal, say 103 

 P.. should not be injected, neither is the test as reliable 

 when applied to animals about to calve, or those in 

 neat or to young calves less than 3 months old. 



The dose of tuberculin depends upon the size of the 

 animal. That distributed under the auspices of the 

 United States Department of Agriculture is diluted, 

 ready for use and requires 2 c c. (40 drops) per 1000 

 pounds live weight. The amount of the commercial 

 tuberculin to be used is always stated on the package. 



The temperature records are commenced 8 to 10 hours 

 after the injection, which is usually made in the evening. 



