700 SPORADIC DISEASES. 



from exposure, or from washing with very cold water whilst 

 the animal is heated, and thereafter inadequately clothed. 



PATHOLOGY. 



Various writers state that the inflammation is situated in the 

 muscular coat. This is evidently a mistake, as the congestion is 

 of the greatest severity in the mucous membrane, the redness of 

 which is of a deep venous colour, approaching to blackness, in 

 patches of various extent, and associated in many cases with 

 extravasation of blood into the canal. Of course, when such 

 extreme congestion of the mucous membrane exists, all the 

 coats are more or less implicated, but the primary and gravest 

 condition is limited to the mucous membrane. 



The submucous tissue is generally much thickened ; there is 

 loss of cohesion, the mucous membrane being easily stripped 

 from its attachments ; some effusion of serum into the intes- 

 tinal canal, causing purging in cattle and dogs ; but in the 

 horse purging seldom or never occurs, though the contents of 

 the bowels may be found fluid after death. This seeming con- 

 stipation results from paralysis or loss of function, and is marked 

 by complete retention of the fcecal matters. In some rare in- 

 stances enteritis may terminate favourably in the horse ; but in 

 the great majority of cases mortification results, or the animal 

 dies from the debilitating efi'ects of hiemorrhage into the intes- 

 tinal canal, or from prostration of the nervous system induced 

 by pain. Gangrene may result in eight or ten hours, the animal 

 rapidly succumbing. In some instances, however, death may 

 not result for several days. In one instance a horse lived for 

 a period of five days, the bowel being found sphacelated, the 

 process of ulceration having commenced at the edges of the 

 gangrenous patch. It is very rarely that ulceration occurs in 

 the horse, but it may be witnessed both in cattle and dogs. 



SYMPTOMS. 



The first noticeable signs are those of abdominal pain ; 

 generally, however, they are preceded by some degree of con- 

 stitutional disturbance, rigors, accelerated breathing, repeated 

 evacuations of small quantities of foeces, and general depression ; 



