26o HOG CHOLERA 



animals died and where the lesions were very few and exceed- 

 ingly varied. In some of them there were healing, intestinal 

 ulcers. The bacillus isolated belonged to the paracolon 

 group.* It may be supposed that possibly many of these 

 mild cases (enzootics) are modified hog cholera. At present, 

 however, such a conclusion does not seem to be fully justified. 



The dietary disorders are determined b}- their history, the 

 irregularity of the lesions, and the failure to find the specific 

 organism of hog cholera in the tissues of the dead animals. 

 An important feature is the fact that the trouble does not 

 extend beyond the herd or herds first attacked or animals fed 

 and kept under like conditions. The amount of loss from 

 these troubles is very large. They are verj' often confused 

 with and mistaken for hog cholera. 



Hog cholera must also be differentiated from a new disease 

 recently described by de Schweinitz, which resembles acute 

 hog cholera symptomaticall}^ but which is caused by an 

 unknown organism that passes through a Chamberland filter. 



The differentiation of hog cholera from swine plague 

 depends upon the specific bacteria. While in typical, chronic 

 cases the intestinal lesions in hog cholera and the lung affec- 

 tions in swine plague are sufficient to distinguish the nature of 

 the disease, in many cases the variations of the lesions are such 

 that diagnoses must depend upon the bacteriological findings. 

 The essential differences between the two species of bacteria 

 are brought out in the comparison appended. 



Bacillus of hog cholera. Bacterium of szaine plague. 



1. Rod-shaped organism with i. Elongated oval organism 

 ends rounded, 1.2 to 2.011 in 0.8 to 1.5 « in length, 0.6 to 0.8 // 

 length, 0.5 to o 8 /< in width. The io thickness. The size varies ac- 

 size varies according to the stage ^°''^'"-? ^o the stage of growth and 



J. ,, J J- ■ • J ^, division and the culture media, 

 ot growth and division and the 



,^ J. 2. From old cultures it usually 



culture media. ^ . ^. , ,,., . ■' 



stains entirelv. When m process 



2. From cultures it stains en- ^^ division as found in the organs 

 tirely . In tissues it usually stains of freshly dead rabbits the extrem- 

 around the periphery leaving a ities stain leaving an unstained 

 light centre. central band, "polar stain." 



*It differed from the hog-cholera bacillus in not saponifying milk. 



