342 



DISEASES OF SWINE 



obtaining virus is to place healthy shoats in an infected feed lot 

 and allow them to contract the disease. These shoats are then 

 bled in the usual manner and the blood so obtained used for in- 

 jection purposes. 



Regardless of the method of securing virus that may be used, 

 a postmortem examination should be made of the virus pigs after 

 slaughter. All the organs usually affected by hog-cholera should 

 be examined and their condition noted. The skin should be noted 

 for evidences of discoloration ; the lymph-glands should be exposed 



Fig. 62. — Exterior of bleeding room at H. K. Mulford plant, Philadelphia. 



and swelling and congestion looked for; the organs of the abdomi- 

 nal and thoracic cavities should be observed, and especially the 

 condition of the intestines, spleen, lungs, and kidneys. There 

 should be sufficient evidence to warrant a diagnosis of cholera, 

 and the more acute in type the disease appears to have been, the 

 more available the virus. Evidence of mixed infection, or of a 

 severe jaundice, is undesirable, and blood from such animals 

 should not be used for virus injections. Especially should this 

 be the case if there are any signs of abscess formation in the body 



