tuberculin-test injection in cattle or bison because tail-bleeding may interfere with 

 test interpretation. 



Veterinarians are legally responsible for properly conducting and evaluating the 

 results of tuberculin tests. Therefore, perform the test yourself; do not delegate the 

 responsibility to a technician. For TB testing in species other than cattle or bison 

 (e.g., cervidae), contact your State animal health official or APHIS-VS Area Office for 

 additional guidance. 



Instructions for Testing 



Step 1 : Forms — 



1. Complete VS Form 6-22, Tuberculosis Test Record. (See appendix D for an 

 example of this form and instructions for completing it.) 



2. Identif)' the animal on the form by its official identification as outlined in the 

 section entitled "Current Animal Identification." 



Step 2: Supplies — 



1. TubercuKn. Use USDA-contract PPD bovis (see table 1). Check the expiration date 

 to be certain that the tuberculin is still valid. 



2. Syringe. Use a disposable 1- or 0.5-cc tuberculin syringe. 



3. Needle. Use a 26-gauge, 3/8-inch-long needle; a larger gauge and longer or shorter 

 needle might allow the tuberculin to leak from the injection site. Use a new needle 

 for each injection. 



Step 3: Injection of Tuberculin — Restrain the animal sufficiently to ensure an 

 accurate intradermal tuberculin injection. 



1. In cattle and bison, injections should be made about 2 to 3 inches distal to the base 

 of the tail just inside the hairline of the caudal fold. 



2. Note scars, defects, and anomalies of the skin in this area on VS Form 6-22 so that 

 they will not be confused with possible test reactions at the time of reading. 



3. Use the caudal fold on either side of the tail; however, note which side 

 you injected. 



4. Clean the area to be injected, but do not use alcohol because it may be irritating to 

 the skin. 



5. Grasp the caudal fold between the thumb and index and middle fingers to 

 stabilize it. 



6. Carefully insert the needle to its full length between the superficial layers of the 

 skin; withdraw it slightly and deposit 0.1 mL of tuberculin. 



7. A small bleb should appear in the skin at the end of the needle. 



Note: It is important to establish a consistent injection technique (i.e., all animals should be 

 injected on the same side of the tail) — particularly when testing large numbers of animals. 



2-7 



