176 



HOG CHOLERA 



dotted with petechiae and occasionally 

 collections of blood (heniatomata) are 

 found in the superficial muscular tis- 

 sue. The brain and spinal cord have 

 not been generally examined. In one 

 case, petechiae were observed on the 

 cerebellum. 



The digestive tract usually is the 

 seat of extensive lesions. The fundus 

 of the stomach is as a rule deeply red- 

 dened ; there may be more or less 

 hemorrhage on the surface, giving 

 rise to patches or larger areas of blood 

 clots. In some cases the small in- 

 testine has submucous ecchynioses 

 throughout its entire length. In the 

 large intestine these ma}' be so numer- 

 ous as to give the membrane a dark 

 red appearance. The intestinal con- 

 tents are now and then found incased 

 in a layer of blood clot. 



{b) The chronic form is perhaps 

 the most common, at least in those 

 epizootics which have been reported. 

 The acute hemorrhagic cases usually 

 die in the beginning of an outbreak 

 and are apt to be overlooked. Follow- 

 ing these are the more protracted ones. 

 In these animals the disease may be 

 limited in its manifestations to the 

 intestine of a pig dead of large intestine although the other or- 

 hog cholera. gans are not exempt from degenerative 



changes. These are due in part to the impairment of the func- 

 tions of the large intestine, consequent fermentations and the 

 absorption of the poisonous products elaborated by the spe- 

 cific bacilli in the spleen and other organs. 



The lesions of the large intestines are necrotic and ulcera- 

 tive in character. The ulcers may be isolated and appear as 



Fig. 40. Ulcers in the 



