12 



FARMERS' BULLETIN 834. 



DISEASES WHICH MAY BE MISTAKEN FOR HOG CHOLERA. 



A few diseases of hogs at times may be mistaken for hog cholera. 

 These are swine plague, tuberculosis, anthrax, necrobacillosis. and 

 lung and bowel disturbances due to worms. 



Swine plague or pig pneumonia; — It is not practicable for the 

 farmer to attempt to distinguish between hog cholera and swine 

 plague, for they are so much alike that even skilled veterinarians 

 may find it almost impossible to distinguish one from the other. 

 Inasmuch as swine plague is rarely found to exist as a separate dis- 

 ease, and usually exists merely as a complication of hog cholera, it 

 is best for the farmer to treat suspected swine plague just as he 

 would a case of cholera. 



Tuberculosis. — The features which distinguish hog cholera from 

 tuberculosis are the facts that in the case of tuberculosis the onset is 

 slow rather than sudden, as in hog cholera ; and that the progress of 

 the disease likewise is slow, it being extremely rare for hogs to die 

 quickly from tuberculosis. It is very possible, of course, for a whole 

 herd to show signs of tuberculosis at about the same time becaiise of 

 having contracted the disease from the same source and at the same 

 time, as through feeding on tuberculous skim milk or following cattle 

 infected with tuberculosis. 



In tuberculosis the changes which may be found in the organs after 

 death consist of whitish or grayish consolidated areas in the lungs, 

 with sometimes a yellowish, cheeselike center. Similar areas, though 

 not so large', may be found in the liver, and in the spleen or melt may 

 be found nodules of varying size, some as large as an acorn. These 

 nodules project above the surface, are light-colored, and when cut 

 are found to consist of a tough, fibrous material which at times may 

 have a cheesy or granular substance in the center. The appearance 

 of the spleen is entirely different from that found in hog cholera. 

 The kidne.ys do not show the small dark spots that are observed in 

 hog cholera, and as a rule are not changed from their normal condi- 

 tion. Tuberculosis frequently affects the lymphatic glands, but these 

 changes can hardly be mistaken for lesions of hog cholera, for, unlike 

 cholera, tuberculosis causes the inner portion of the gland to break 

 down into a yellow, cheesy mass which in the advanced stage of the 

 disease may contain small, hard, gritty particles, resembling grains 

 of sand. 



Anthrax. — Hogs rarely are affected with anthrax, but when this 

 disease does occur it might readily be mistaken for the acute type of 

 hog cholera. The distinguishing features of anthrax in hogs are the 

 marked swelling of the throat and tongue, with frequentty a bloody 

 froth in the mouth. Anthrax in hogs usually follows the disease in 



