180 SWINE DISEASES 



rarely will there be evidence of catarrhal pneumonia, 

 except in those cases of the simultaneous occurrence of 

 hog cholera and swine plague. The lesions of simple 

 catarrhal pneumonia occur in the lower portions of the 

 lung, and are the same when it occurs as a complication 

 of hog cholera as in, the primary affection of catarrhal 

 pneumonia which has been previously described (p. 88). 



Pleurisy may accompany the pneumonic form of hog 

 cholera, but it is exceptional to observe such cases. The 

 pleurisy may be serous, fibrinous, or hemorrhagic, and 

 in exceptional cases it may become purulent or septic. 



Although subepicardial and subendocardial hemor- 

 rhages are typical of the pure, uncomplicated hog cholera, 

 these lesions are more extensive in the pectoral form of 

 the disease. 



Mixed form. The mixed form of hog cholera consists 

 of the septicemic form plus complications of the intestinal 

 and pectoral forms. This form of hog cholera is prob- 

 ably more prevalent than any other type described, and 

 this fact accounts for the difficulty that is frequently 

 encountered in making a diagnosis. 



All of the different forms of hog cholera described are 

 frequently found in one herd of hogs. Occasionally pecu- 

 liar combinations of lesions are observed, and in some 

 instances it is not possible to make a diagnosis until 

 several autopsies have been performed. In one instance 

 four hogs were autopsied and hemorrhagic gastritis was 

 the only lesion found. Two days later another hog was 

 autopsied, and revealed typical lesions of hog cholera. 



Symptoms. Symptoms of hog-cholera are as varia- 

 ble as the lesions. For convenience in describing the 

 symptoms will be considered in four groups corresponding 

 to the four types mentioned in the consideration of 

 lesions. 



Septicemic form. The most acute or so-called peracute 

 cases are frequently found dead, having evidenced no 

 symptoms. The ordinary acute cases evidence the fol- 

 lowing symptoms, usually in the order mentioned. The 

 affected animals are inclined to isolate themselves and 



