288 



SWINE PRACTICE 



cholera; however, they may oeevir in any other septicemia. The 

 clianges of the bone marrow, although occurring to a kss degree in 

 other septic conditions, are among the most common lesions of cholera, 

 but this lesion is absent in some of the peracute cases. Petechial 

 hemorrhages are also of common occurrence in swine erysipelas, but 

 this disease can be differentiated from cholera by the demonstration of 

 the organism of swine erysipelas in the blood or splenic pulp. 



The principal diagnostic lesions occurring in cases of cholera are 



Fig. 78. Mucous membrane of the bladder. A, normal; 

 flammation due to hog cholera. 



B, showing in- 



subserous and submucous hemorrhages, congestion and hemorrhages 

 of the lymph nodes, and the discoloration of the bone marrow. 



In the diagnosis, the history of the outbreak, and particularly the 

 distance from known cases of cholera and whether or not anj^ swine 

 have recently been introduced, must always be taken into considera- 

 tion. Finally, it must be understood that the only absolute method 

 for the diagnosis of cholera at this time is the inoculation of a known, 

 healthy, susceptible pig with from one to five cubic centimeters of 

 filtered blood from the suspected animal. 



Prognosis. — Cholera is a very fatal disease. The mortality varies 

 from sixty to ninety-eight per cent. 



