BIOLOGICAL THERAPEUTICS 553 



on their labels and literature the amount of Koch's old tuberculin con- 

 tained per mil. 



Thermic tuberculin when injected subcutaneously, not containing any 

 germs, is unable to produce the disease or any kind of injury to a healthy 

 animal. On the other hand if the animal is affected with tuberculosis a 

 rise in temperature will follow the administration of tuberculin. The 

 following instructions on tuberculin testing are issued by the Bureau of 

 Animal Industry: 



The Subcutaneous Test 

 The following directions for tuberculin testing are taken from 

 the B. A. I. publication on "Instructions concerning the work of the 

 tuberculosis eradication division." 



The subcutaneous test is the official test of the United States Bureau 

 of Animal Industry. Carefully and conscientiously applied, with good 

 judgment exercised in both its administration and interpretation, it is 

 regarded as highly effective. It is not a suitable test to apply generally 

 when the animals have high temperatures and it may not be practicable 

 in cases of cattle which cannot be controlled easily. 



Directions for the Application of the Subcutaneous Test. 



1. So far as practicable, the cattle should be stabled under usual 

 conditions and with usual surroundings. 



2. The cattle should be fed and watered in the customary manner, 

 except that it should be done only immediately after the measuring of 

 temperature. Occasionally it is advisable to limit the quantity of con- 

 centrated food given animals under test. This is especially true if large 

 quantities of that kind of food are allowed. 



3. A careful physical examination of each animal should be made 

 before or during the application of the test. 



4. During the period immediately before the injection of tuberculin 

 each animal's temperature should be taken at least three times at not 

 less than two-hour intervals. Care sl\,ould be taken to let the thermom- 

 eters remain inserted for a sufficient length of time to insure correct 

 reading. Animals showing evidence of any acute disease or condition or 

 showing extensive pus formations should not be injected with tuberculin. 

 Any animal showing pronounced abnormal preliminary temperatures like- 

 wise should not receive the tuberculin test. Inquiry concerning the his- 

 tory of the herd should be made, and it should be ascertained, if pos- 

 sible, whether any animal in the herd has ever given a positive reaction 

 to tuberculin, the number of tuberculin tests applied to the herd pre- 

 viously and, also whether any cattle in the herd have been treated at any 

 time in any other manner with tuberculin. The information thus obtained 

 should be used in determining the method to be employed in the tuberculin 

 testing of the herd. 



5. The hypodermic syringes and needles should be disinfected be- 

 fore testing any herd with tuberculin. Before being used for the 

 injection of each animal, needles should be washed in a disinfectant 

 solution. A five-per-cent solution of carbolic acid is suitable for steriliz- 

 ing the instruments. Open bottles of tuberculin should be protected from 

 contamination. Thermometers should be sterilized before the temperature 

 is taken, and should be dipped in a disinfectant solution before and after 



each reading. Digitized by Microsoft® 



