66 Swine Erysipelas. 



vessels. The accumulation of the bacilli in certain parts^ is 

 probably favored by their being engulfed by leucocytes which 

 then adhere to the intima of the vessel. In chronic cases when 

 they become attached to the valves of the heart they produce an 

 affection of the valvular tissue (endocarditis verrucosa s. bacil- 

 losa) or a bacillary thrombosis develops in some of the vessels 

 of the corresponding valves. 



In some cases especially those in which the bacilli are not 

 very virulent, their multiplication occurs only in the lymph 

 spaces of the skin whereby reddening of the skin with circum- 

 scribed edema develops (urticaria, diamond-skin disease) which 

 SJ^nptoms disappear after the death of the bacilli. 



These changes prove that the erysipelas bacilli produce toxins in 

 the body tissues, and in cases of general infection the fever, depres- 

 sion, paralysis and finally death may also be traced to the action of 

 the toxins. This is substantiated by the experience that hogs some- 

 times die as a result of a cutaneous infection with the symptoms of 

 the disease, yet bacilli are only found at the point of inoculation and 

 in the immediately surrounding tissue (Preisz). Until the present 

 time, however, it has been impossible to demonstrate toxic substances 

 either in artificial cultures of erysipelas bacilli or in the carcasses of 

 animals succumbing to the disease. (According to Petri & Maassen, 

 erysipelas bacilli produce toxin in media containing hydrogen sulphide.) 



Anatomical changes. In the acute form of hog erysipelas 

 the post mortem on animals which have succumbed to the 

 disease shows in most instances only slight changes in the inter- 

 nal organs. The mucous membrane of the stomach, particularly 

 at the pylorus, shows an inflammatory swelling, reddening, and 

 numerous small hemorrhages. The surface is covered with a 

 sticky, glassy mucus. The mucous membrane of the small intes- 

 tine, especially in the duodenum and ileum, appears catarrhal 

 and congested. The solitary follicles and Peyer's patches are 

 also swollen, the superficial layer of the mucous membrane may 

 sometimes show desquamation and even ulceration (Schotte- 

 lius). Small ulcers also occur on Bauhin's valve as well as 

 in the large intestine. 



The spleen is usually only slightly swollen and congested. 

 The liver and kidneys show indications of cloudy swelling; the 

 cortical substance of the latter is mostly darker and often 

 mottled by dark red points (glomerulonephritis). The lungs 

 are hyperemic and edematously infiltrated ; sometimes they are 

 atelectatic at their borders as a result of catarrhal inflamma- 

 tion. All the lymph glands are markedly swollen, rich in blood 

 and fluids. The serous membranes may be covered with fine 

 fibrin membranes. Small hemorrhages also occur with relative 

 frequency on the serous and mucous membranes, under the epi- 

 and endocardium as well as in the subcutaneous connective 

 tissue. ' - 



