SWINE ERYSIPELAS 319 



infection. Hogs from three months to one year are most 

 susceptible. Sucklings and old animals are usually quite 

 resistant. 



Necropsy. — In the acute form very little change is noted. 

 The small intestines are catarrhally inflamed. Peyer's 

 patches and the solitary follicles are swollen and small 

 ulcerations are noted. The spleen is somewhat enlarged. 

 Ecchymoses and petechiae are prone to appear in the mucous 

 and serous membranes, especially in the epi- and endocardium 

 and in the subcutaneous connective tissue. The kidneys are 

 swollen, and on section the cortex is grayish-red dotted with 

 punctiform hemorrhages, the medullary substance dark. As 

 a rule the lungs are not involved. In chronic cases the prin- 

 cipal lesion is found in the heart, the atrioventricular valves 

 showing lesions of verrucous or ulcerous endocarditis. 



Symptoms. — ^The period of incubation is three to five days. 

 The clinical symptoms vary, but the following forms are 

 fairly well distinguished. 



(a) Skin Form. — Urticaria Type (" Diamond Disease"?). — 

 After a short period, during which the hog seems languid 

 and fails to eat well, there appear in the skin on the sides of 

 the chest, back, neck and legs, sometimes all over the body, 

 violet-colored spots and sometimes vesicles. The spots are 

 often rectangular or rhomboidal in form and are elevated 

 above the surrounding skin. They are usually about the size 

 of a 50-cent piece, larger by confluence. Sometimes vesicles 

 occur upon them which break, the discharge drying to brown- 

 ish crusts. As a rule, symptoms of fever, languor, anorexia, 

 constipation, paraplegia, conjunctivitis, and vomiting attend 

 the exanthema. The skin eruption usually disappears in 

 from one to two weeks. In some cases necrosis of the skin, 

 especially of the ears, tail, or digits takes place, leading to 

 sloughing and healing, with pronounced scar formation. 



(b) Septicemic Form. — This form very much resembles the 

 septicemia (explosive) form of hog-cholera (see this). The 

 skin is usually highly reddened, especially on pendent portions 

 of the body. The red colorations have an erythematous char- 

 acter, finger pressure temporarily removing them. Vesicle 

 formation and necrosis may also occur, In severe cases there 



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