DIFFERENTIAL DIAGNOSIS 1 27 



the medullary portion of a very dark-red color. Frequently 

 catarrhal nephritis occurs as a complication. 



The acute swelling of the spleen arises in consequence of 

 an acute hyperemia, with an increase of the cellular constitu- 

 ents of the pulp, in which case the organ is enlarged, but not 

 softened as in anthrax. The pulp is of a purple color, moder- 

 ately soft and free from hemorrhages. 



There is cloudy swelling and enlargement of the liver. 

 The surface of sections has a grayish-brown color, and the 

 acini are widened. The muscles are gray in color, soft, flac- 

 cid, watery, glistening and sometimes they are sprinkled with 

 hemorrhages. They give the general appearance of boiled 

 flesh. The myocardium shows similar spotted changes, and 

 punctiform hemorrhages beneath the endocardium. In the 

 abdominal and thoracic cavities and pericardium, there may 

 be found small quantities of an orange-colored, clear fluid, 

 which may be mixed with a flaky coagulum. 



Many English veterinarians regard the occurrence of 

 more or less luxuriant vegetations on the valves of the heart 

 to be so common that it is to be considered almost diagnostic. 

 It would appear from the literature that this endocarditis is 

 not nearly so common in continental Europe. The lungs 

 remain unchanged, or at most exhibit a post-mortem edema. 

 By microscopic examination, the specific bacteria are found 

 everywhere in the body, especially in the spleen and kidneys, 

 and to a less extent in the blood. 



The duration of the disease varies from i to lo days. In 

 types of moderate severity it runs from 3 to 4 weeks. 



The prognosis is unfavorable. There is from 20 to 80 per 

 cent mortality. 



§ 114. Differential diagnosis. Swine erysipelas is to 

 be differentiated from : 



I. Hog cholera and swine plague. The frequent red- 

 dening of the skin in these diseases together with the modified 

 lesions so frequently observed may cause confusion. The 



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