152 Agricultural Bacteriology. 



mals. It is found in England, Germany, and other 

 European countries. 



Symptoms. The hog when ill usually shows much 

 the same symptoms, whatever the trouble may be. The 

 disease develops from seven to fourteen days after in- 

 fection occurs. When the disease appears in a herd, 

 some of the animals are certain to die after a short ill- 

 ness of a few hours, or at longest a few days, of acute 

 cholera. Others show signs of illness for a much longer 

 period and some recover. The animal acts dumpish, and 

 tries to hide. The appetite usually is very good. The 

 skin of the ears, nose, abdomen, and inside of the thighs 

 is reddened. "With chronic cases weakness of the limbs, 

 especially the hind legs, develops and the animal moves 

 with difficulty. 



Post-mortem examinations. The disease often can- 

 not be diagnosed with certainty from the symptoms, but 

 an examination of the carcass is necessary. In the acute 

 type one of the most common and striking changes is in 

 the spleen. This organ is often much enlarged, soft and 

 very full of blood. Hemorrhages are found in various 

 parts of the body, especially on the lining of the abdomen 

 and chest, and on the inner wall of the intestine. The 

 intestinal contents may be surrounded by a blood clot. 

 In the chronic form the most characteristic lesions are 

 found in the large intestines in the form of ulcers on the 

 inner wall. The ulcers may be as large as a hickory nut 

 and because of the rounded form are called ''button 

 ulcers. ' ' The death of the tissue near the ulcer may be 

 so extensive as to cause a perforation of the wall of the 

 intestine, thus giving an opportunity for the intestinal 

 contents to escape into the abdominal cavity. Such a 



