HOG-CHOLERA— SWINE FEVER 359 



able condition. Too often a close discrimination between 

 the infected and uninfected is not made. In transit or soon 

 after arrival at their destination the disease may break out, 

 infecting the railway cars, shutes, pens, etc. Hog-cholera, 

 therefore, is spread over great areas, and especially along 

 lines of traffic. 



A transmission of the disease along the course of a flowing 

 stream is probable, the current carrying the infection. 



Necropsy. — (a) Septicemic Form. — ^Lesions, as in hemor- 

 rhagic septicemia. Petechiae and ecchymoses of the skin, 

 serous membranes and of the mucous membrane of the 

 gastro-intestinal tract, especially of the bowels. In the latter, 

 accumulations of clotted blood may be found; the lymph 

 glands are swollen and blood-shot; the parenchymatous 

 organs congested, the spleen little if at all swollen. The 

 petechise over the kidneys give them a spotted appearance, 

 known as "turkey egg" kidney. On the serous membranes 

 fibrinous exudates appear; catarrh of the stomach and small 

 intestine is also noted. 



(b) Intestinal Form. — ^The most characteristic lesions are 

 noted in the large bowels, especially in the cecum. There 

 appear in the mucosa and submucosa, flat, round, hard, 

 elevated, yellowish, greenish-yellow or gray areas of necrosis. 

 The areas vary in size from a pin-head to a twenty-five cent 

 piece. The larger ones are commonly known as "button 

 ulcers." 



(c) Pectoral Form. — ^The lungs present the signs of pneu- 

 monia (croupous, catarrhal or mixed) with serofibrinous 

 pleuritis and pericarditis. In subacute or chronic cases 

 multiple necrotic foci are present in the lung with caseation 

 which may involve the lymph glands. (Most of these cases 

 are probably swine plague.) 



The following necropsy lesions speak for hog-cholera in 

 outbreaks occurring in the United States : 



(a) Petechise and ecchymoses of skin. 



(b) Petechise and ecchymoses of serous membranes, 

 especially of the pleura, epicardium and peritoneum over the 

 kidneys ("turkey egg kidney"). 



(c) Swollen lymph glands. 



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