220 Veterinary Medicine. 



rarely actually fatal ones. Acute and fatal congestive lesions of 

 the small intestine from verminous embolism, occur only when 

 several adjacent divisions of the artery are blocked at once, and 

 this is a rare occurrence. 



The right bundle of branches furnishes the only two arteries 

 which are supplied to the caecum and the only artery furnished 

 to the first half of the double colon. The ileo-csecal branch is 

 less involved, first, because being less dependent and smaller, it 

 is less likely to recieve an embolus, and, second, because any lack 

 of blood supply is .counterbalanced by the free anastomosis with 

 the last ileac division of the left bundle. When the embolus 

 blocks the undivided trunk of the right bundle this same princi- 

 ple comes into play, the free supply of blood from the posterior 

 branch of the left bundle supplying blood through its anastomosis 

 with the ileac and caecal branches of the right. 



But when the emboli are lower down, in the caecal branches of 

 the right bundle, or in these and the colic branch, arrest of the 

 circulation in the intestinal walls ensues, followed by paresis, 

 passive congestion and hemorrhage. The caecum and double 

 colon thus become the seats of the grave and fatal lesions of ver- 

 minous embolism. In a specimen in the N. Y. S. Veterinary 

 College a chain of aneurisms extends about six feet. 



The resulting lesions are to be variously accounted for. The 

 stagnation of the blood in the vessels below the embolus, deter- 

 mines a speedy exhaustion of its oxygen and increase of its carbon 

 dioxide, so that it is rendered unfit to maintain the normal nutri- 

 tion and functions of the part, and the capillary and intestinal 

 walls are alike struck with atony or paresis. The blood filters 

 into the stagnant vessels slowly from adjacent anastomosing 

 trunks, and the liquor sauguinis exudes into the substance of the 

 tissues and lumen of the intestine, leaving behind the greater 

 part of the blood globules so that the stagnant blood is rendered 

 more and more abnormal in composition. The walls of the capil- 

 laries soon lose their cohesion as well as their coutractibility, and 

 giving way at different points, allow the escape of blood into the 

 tissues, bowels and peritoneal cavity. It has been further claimed 

 that the emboli already infected and in process of degeneration 

 communicate this to the walls of the vessels and to the stagnant 

 blood, hastening the process of degeneration and rupture. 



