126 



Diseases of Poult ry 



ments with tuberculin prepared from the avian bacilH. 



These authors injected this tubercuhn within the layers of 

 the skin (intracutaneous) in the comb and 

 wattles. The results indicate that this 

 method is reasonably satisfactory. Sum- 

 marizing the results of their tests on 601 

 birds, these authors found that 98 per cent 

 of the birds showing tuberculous lesions 

 reacted to the test. Only 8 per cent of the 

 non-reacting birds showed lesions. Numer- 

 ous previous investigators had obtained 

 negative results with the subcutaneous, 

 ophthalmic and cutaneous method of ap- 

 plication. It appears that for birds the 

 intracutaneous method is the only one to 

 be considered of value. 



Technique of making the injection is very 

 important according to Van Es and Schalk. 

 Care must be taken that the injection is 

 neither too deep nor too superficial. A small 

 caliber syringe with a very fine needle (No. 

 26 or 27) is used. 



Owing to the denseness of the tissues, 

 especially the comb, it is often difficult to 

 inject even a small quantity, and consider- 

 able pressure is required to force the tu- 

 berculin into the tissues. The amount 



Fig. 17. — Syringe injected into each bird was not carefully 

 bercuiin tes^t for measured but varied between 3^ and 2V of a 

 chickens. (Af- cubic centimeter of a 50 per cent avian tuber- 

 sdilk') ^' ""''"^ ^"^"^- This tuberculin was prepared in the 



usual way. 

 Owing to its looser texture the wattle proved to be the 



best place for the injection. The results of the tests were 



