330 ACUTE GENERAL INFECTIOUS DISEASES ' 



The following necropsy lesions speak for hog cholera in 

 outbreaks occurring in the United States : 

 (a) Petechia and ecchymoses of skin. 

 . (b) Petechia; and ecchymoses of serous membranes, espe- 

 cially of the pleura, epicardium and peritoneum over the 

 kidneys ("turkey-egg kidney"). 



(c) Swollen lymph glands. 



(d) Button ulcers in the bowel (especially cecum and 

 colon). 



(e) Absence of pronounced splenic enlargement. (In 

 subacute and chronic cases the spleen may be smaller than 

 normal.) 



Symptoms. — The period of incubation varies from four to 

 eighteen days, usually it is eight to ten days. The symptoms 

 of hog cholera are not particularly characteristic. In the 

 beginning of an outbreak the first warning given is the finding 

 of a dead hog in the herd. Later another may be found. 

 These losses may continue for a week or so when a number of 

 swine show signs of disease. The symptoms will vary with 

 the outbreak and the individual, i. e., some cases showing the 

 pulmonary, others the intestinal type of the disease, etc., as 

 follows : 



(a) Septicemic Form. — Barring peracute cases which die 

 suddenly without having shown marked symptoms, the hog 

 with acute cholera loses appetite, seems sluggish, weak, and 

 is apt to crawl off in a corner or buries itself in the straw-pile. 

 They usually do not come to feed when called, and if driven 

 out of their seclusion are disinclined to move, hold the back 

 arched, the curl is gone from the tail, and the ears droop. 

 On the surface of the abdomen, the inside of the thighs, and 

 around the ears and neck smaller petechia? or larger ecchy- 

 moses are noted. A quite characteristic symptom is con- 

 junctivitis, the exudate causing the lids to adhere. Vomiting 

 is not uncommon. At first the bowels are constipated, but 

 later diarrhea sets in, the feces being often blood-stained. 

 The temperature is high. 



(b) Bowel Form. — This type of cholera involves not only 

 the intestines but the whole digestive tract. The symptoms 

 either follow those of the septicemic form or may come on 



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