COMPLICATIONS 25 



mune hogs do not suffer from " swine plague " if 

 we except the cases in which it is said to appear 

 in the first month subsequent to serum-virus treat- 

 ment, and which in reality have their origin in 

 the hog cholera virus used. 



Acting as a secondary invader in hogs suffering 

 with cholera, in those badly infested with lung 

 worms, and very probably as a primary microbian 

 cause in those weakened as a result of shipping, 

 Bact. suisepticum regularly produces a rather 

 characteristic bronchopneumonia, and hastens or 

 causes death. In those cases in which it acts as a 

 secondary invader it produces pneumonia so rap- 

 idly and regularly that the lesions due to the pri- 

 mary cause are often obscured or overlooked. 

 Cholera immune farm hogs kept in exceedingly 

 bad sanitary surroundings and exposed regularly 

 to damp and inclement weather, have not been 

 shown to suffer from a rapidly transmissible and 

 fatal pneumonia caused by this organism. There 

 is, though, some experimental evidence that it oc- 

 casionally produces pleuritis or possibly slight 

 pneumonic lesions from which most hogs recover. 



B. suipestifer (B. cholera suis) is another or- 

 ganism which may often be isolated from various 

 parenchymatous organs of hogs dead in outbreaks 

 of cholera. It is a short, motile rod, belonging 

 to the colon group. In 1885 it was described by 

 Salmon and Smith as the cause of epizootic hog 



