Biological Therapy 



175 



7. The measurements of temperature following the in- 

 jection of tuberculin should commence at the eighth hour 

 and be continued every two hours until the twentieth hour 

 after injection, when, if there is no tendency for the tempera- 

 ture to rise, the test may cease. Temperatures upon cattle 

 which are showing a rising tendency following the injection 

 of tuberculin should be measured more frequently. 



8. Suspected cattle should be submitted to a retest 

 after the expiration of not less than 60 days. This class of 

 cattle and those which show possible physical evidences of 

 tuberculosis, emaciation, old age, or which have been tested 

 repeatedly should receive double the dose of tuberculin indi- 

 cated above. 



9. Experience has shown that animals, especially those 

 of doubtful record, receiving large doses of tuberculin, may 

 respond early to the test, and inspectors are advised, 

 wherever practicable, to obtain temperatures at from the 

 fourth to sixth hour following the use of large doses of 

 tuberculin. 



10. A rise of 2° F., or more, above the maximum tem- 

 perature observed prior to the injection of tuberculin, or a 

 temperature above 103.8° F., should be regarded as an indica- 

 tion of tuberculosis, provided the temperature reaction 

 shows the characteristic rainbow curve. 



11. Animals which after injection show a rise of tem- 

 perature of 2° F., with a maximum of between 103° and 103.8° 

 F., as well as those which show a rise of less than 2° F., with 

 a maximum temperature of 103.8° F., are regarded as sus- 

 picious. The presence of a general systemic reaction or a 

 typical curve should be considered in determining the classi- 

 fication between suspects and reactors. 



THE INTRADERMAL TEST. This is made by inject- 

 ing a very small quantity (0.1 c.c. for young calves to 0.2 c.c. 

 for adult animals) of specially prepared tuberculin INTO the 

 skin. This is a very delicate test, which requires skill and 

 constant practice. The tuberculin should be injected into 

 the dermal tissue, special care being used to prevent its sub- 

 cutaneous injection. For this purpose a special syringe and 

 needles are required. Regular dental syringes with small 

 calibre needles one-fourth inch in length are quite satis- 

 factory. 



