298 VETERINARY BACTERIOLOGY 



Kitt and Mayr, in 1897, showed that it is possible to secure a 

 protective serum from the horse and other animals, as goat and 

 swine, by injections of living fowl-cholera organisms, and this 

 serum, when injected in suitable quantities into susceptible ani- 

 mals, will protect them from injections of virulent bacilli. Schrei- 

 ber, in 1899, elaborated upon an observation of the preceding in- 

 vestigation that animals immunized against swine-plague bacilli 

 (B. suisepticus) were likewise immune to fowl cholera. In 1902 

 he gave the name " septicidin " to a polyvalent serum which he 

 prepared by immunization with B. suisepticus, B. avisepticus, and 

 B. cholerce suis. The reports relative to the efficiency of this 

 serum are conflicting. It has not come into general use. Hertel, 

 in 1902, reported that by intravenous injections of dead bacteria 

 followed by living bacteria into an ass he secured a serum which in 

 injections of 0.5 c.c. protected pigeons against 10,000 times the 

 normal lethal dose of the organism. Ligniere and Spitz have also 

 prepared a polyvalent serum, using the Ligniere vaccine noted 

 above. There is no record of a practical utilization of this method. 

 Kitt and others, in 1904, have described sera which protect fowls 

 experimentally inoculated with B. avisepticus, but, like the others 

 described, these have not come into general use. It may be con- 

 cluded, therefore, that while immunization against fowl cholera, 

 either by vaccination or the use of antisera, has been shown to be 

 possible, it has not been proved practicable. 



Bacteriologic Diagnosis. Stained mounts of the blood which 

 reveal the presence of gram-negative bacilli showing prominent 

 bipolar staining are diagnostic. The bacillus may be readily iso- 

 lated in artificial media. Whether or not serum reactions, par- 

 ticularly agglutination, might be utilized in diagnosis is not known. 



Transmission. The disease is supposed to be transmitted from 

 bird to bird by ingestion of food or water fouled with excretions 

 containing the specific organism. 



Bacillus suisepticus 



Synonym. Bacillus suicida. 



Disease Produced. Swine plague; Schweineseuche. 

 Loffler and Schiitz, in 1886, published results which established 

 the identity of swine plague as a specific disease by the discovery 



