INFECTIOUS DISEASES 



225 



The intradermal tuberculin test is most applicable to 

 swine. This test is made by the injection into the 

 dermis at the base of the ear of from three to five minims 

 of ordinary tuberculin.* The reaction consists of a 

 dense swelling at the point of injection and becomes 

 most prominent on the second or third day after injection. 



Fig. 28. TUBERCULOSIS OF THE PLEURA. 

 A. Rib. B. masses of tubercles. 



The subcutaneous tuberculin test may be used, but 

 it is not as applicable to swine as it is to cattle. The 

 ophthalmic test may also be employed in swine. 



Microscopic examination may be made of the various 

 discharges for the purpose of identifying the tubercle 



*The Bureau of Animal Industry have issued an order that all swine used for tail 

 bleeders in serum production must be tested with especially prepared intradermal 

 tuberculin. The object of this order is not clear, as the ordinary tuberculin is as 

 efficient as special intradermal tuberculin 



