136 DISEASES OF SWINE 



or cap is brushed off from the lesion we find beneath a typical 

 hollowed out, ulcerated surface. This may be very superficial, 

 and only involve the lining membrane of the bowel, or it may 

 extend deeply into the muscular and even to the serous or outer 

 coat of the bowel. In some rare cases the ulcer becomes so deep 

 seated that it perforates through the bowel, and allows the fecal 

 matter in the bowel to escape into the abdomen, and results quickly 

 in the development of an inflammation of the peritoneum — perito- 

 nitis — which rapidly proves fatal. 



These ulcers are the typical lesion of chronic hog-cholera, and 

 when they are present the postmortem diagnosis is easily made. As 

 just stated, however, it must be remembered that there may be an 

 entire absence of these ulcers in the most severe form of cholera, 



(crs of hog-cholera. (Photo by Dr. Geo. R. White.) 



viz., the acute type; so that one cannot depend absolutely on the 

 finding of ulcers for establishment of the diagnosis of cholera. 



As to the number of these ulcers which may be present, there is 

 no fixed rule. In some cases only a very few, perhaps only one or 

 two, may be found. In other cases they are scattered hke grains of 

 shot all through the lower part of the intestine. In some very 

 severe and long-drawn-out cases there may be so marked an ulcer- 

 ation of the ileum as to give the appearance of one large ulcer in- 

 volving the entire surface of the bowel. 



Ileocecal Valve. — The ileum of the small intestine empties into 

 the cecum, which is the beginning of the large bowel. The cecum 

 is what is commonly known as "the black gut." At the point 

 where the ileum opens into the cecum there is a small valve, made 

 by a folding upon itself of the lining membrane of the bowel. 



