28 HOG CHOLERA 



B. pyocyaneus is pathogenic for pigeons, guinea 

 pigs and rabbits. In swine, it is not regularly so, 

 but under certain conditions it assumes great 

 pathogenic significance. We have failed to pro- 

 duce disease by feeding cultures of it or by spray- 

 ing them into the nostrils of healthy pigs, while 

 subcutaneous doses produced nothing more than 

 an occasional local abscess. Moderate intrave- 

 nous doses of suspensions containing it cause 

 dyspnea, chilling or spasms to appear immedi- 

 ately, and death, preceded by paralysis, usually of 

 the hind quarters, often takes place in a day or 

 two. This paralysis is observed in rabbits as well, 

 and must be regarded as a more or less constant 

 but nevertheless specific action on the part of the 

 organism. According to Hutyra, cultures of B. 

 pyocyaneus inoculated directly into the ethmoid 

 mucosa in young pigs, produce disease similar to 

 the catarrhal rhinitis observed in Germany. 



Under natural conditions certain predisposing 

 factors, among which early age, lung worms, hog 

 cholera virus and long confinement in very dusty 

 quarters are most important, prepare the ground 

 so that B. pyocyaneus exerts its pathogenic pow- 

 ers. We have observed its effects following 

 hyperimmunization during the process of anti-hog- 

 cholera serum preparation, the hypers developing 

 a fatal pneumonia in a few days following a large 

 intravenous dose of hog cholera virus. 



