l8o HOG CHOLERA 



seventh da}'. At the point of inoculation a pasty mass extends to abdo- 

 men, only subcutis involved. Spleen engorged. Single acini in the liver 

 are completely necrosed, yellowish white. In both organs, hog cholera 

 bacteria. Cultures from spleen pure. (Report on hog cholera, 1S89. ) 



§ 138. Differential diagnosis. Hog cholera is to be 

 differentiated from a great variety of dietary disorders and 

 poisoning from alkalies and possibly from other chemicals 

 which may get into their food. Powdered soap has been found 

 to produce, when given in sufficient quantities, a series of 

 symptoms quite similar to those of hog cholera. In addition 

 to the many as yet etiologically undetermined disorders often 

 giving a high mortality and popularly called hog cholera, infec- 

 tious pneumonia or swine plague and tuberculosis are to be 

 distinguished from it. 



It sometimes happens that swine when kept under good 

 hygienic conditions suffer from disorders which in their symp- 

 toms resemble hog cholera, but anatomically the lesions are 

 varied and irregular. A few such enzootics have been studied. 

 A few have been described. In one instance B. coli com- 

 munis seemed to stand in a casual relation to the trouble. 

 Recently the writer has studied two similar enzootics where 

 several animals died and where the lesions were very few 

 and exceedingly varied. In some of them there were healing, 

 intestinal ulcers and the bacillus isolated belonged to the para- 

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

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

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



The dietary disorders are excluded from the 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 docs not 

 extend beyond the herd or herds first attacked or animals fed 

 and kept under like conditions. 



In differentiating hog cholera from swine plague much de- 

 pends upon the specific bacteria. While in typical chronic cases, 

 the intestinal lesions in hog cholera and the lung affections in 

 swine plague are sufficient, in many cases and outbreaks the 

 variations of the lesions are such that diagnosis must de- 



