276 Hog Cholera. 



red spots frequently appear on the finer parts of the skin, which 

 develop as a result of a simple dilation of the vessels. Later 

 small vesicles form in these places, and soon the superficial 

 epithelial layer separates in fine lamellae. The abdomen some- 

 times shows numerous punctiform hemorrhages, which remain 

 noticeable for a long time even after recovery. Occasionally 

 urticaria may develop, when vesicles will appear on the flat, 

 raised lesions (Schindelka). In some cases tlie bristles may 

 fall out on different spots or over the entire body, animals with 

 dark pigmented skin may become white, and if tlie animals re- 

 main alive white bristles grow on the bald places, which however 

 may later be replaced by black. 



Diagnosis. The clinical symptoms do not afford sufficient 

 grounds for the establishment of a positive diagnosis. Although 

 they cause a well-founded suspicion of hog cholera, especially in 

 already affected herds or if the disease is prevalent in tlie local- 

 ity, the determination however must be made dependent on 

 the autopsy findings. As in accordance with the present state 

 of our knowledge the bacillus suipestifer or other bacteria of 

 the hog cholera group under natural conditions produce only 

 in the body weakened by the filtrable cholera virus follicular 

 lesions on the intestinal mucous membrane, and the ulcerations 

 and buttons resulting from these with simultaneous caseation of 

 the regional lymph glands, these changes must be considered as 

 characteristic of hog cholera. Therefore where they are pres- 

 ent the diagnosis of hog cholera may be established without 

 consideration of accessory circumstances. 



The fact that it is sometimes possible to produce the anatomical hog cholera 

 artificially, with the bacillus suipestifer alone, does not indicate that this occurs 

 under natural conditions, especially as positive results have only been obtained in 

 feeding experiments with very large quantities of culture. Glasser is nevertheless 

 of the opinion that an organism which he isolated from two apparently sponta- 

 neously affected pigs, and which biologically differed from the bacillus suipestifer 

 resembling more the human typhoid bacillus (Bac. typhi suis), may independently 

 produce a contagious epizootic infection (typhus of hogs). However the occurrence 

 of such a spontaneous enzootic, or even epizootic, has not been confirmed from any 

 other source. According to a preliminary rejtort of Stedefeder the bacillus suipes- 

 tifer also may produce spontaneous affections independently, without any pre- 

 existing accessory influence of an ultravisible virus. 



Contrary to the formation of intestinal lesions, the presence 

 of a necrotic pneumonia, even in a typical form, has not the 

 same pathognomic significance, as this form may occur inde- 

 pendently without any participation of the filterable hog cholera 

 virus, and in such case it must be considered as pure swine 

 plague. , The decision whether in a single case one is dealing 

 with pure swine plague, or hog cholera with swine plague symp- 

 toms, is in practice sometimes very difficult. If besides the 

 inflammatory infection of the lungs there are at the same time 

 scabs, round ulcers with discolored covering, or even button- 

 like scabs on the mucous membrane of the intestinal canal, with 

 or without swelling of the lymph glands, a cholera infection 



