220 BOVINE PATHOLOGY. 



central line. Animals with the heart exposed in any of 

 these abnormal positions soon die from injury to the 

 organ. 



Section 2. — Op the Arterial System. 



In injected specimens we are struck with the smallness 

 of the arteries of the ox as compared with those of the 

 horse. They are, in fact, proportional rather to the size 

 of the heart than to that of the veins or the general 

 bulk of the body. The posterior aorta is an exception 

 to this, for the coeliac axis is remarkably large. The 

 principal diseases of arteries are degenerations of various 

 kinds, which generally occur in old animals. These are 

 atheromatous, where chronic inflammation has brought 

 about fatty degeneration of the endothelial cells of the 

 inner coat with thickening and cholesterin deposit in its 

 deepest layer. This condition results from over energetic 

 action of the heart long continued. We have no record 

 of acute arteritis. A case of tuberculous degeneration of 

 the ovarian arteries is given in the ' Edinburgh Veterinary 

 Review,' vol. i, p. 379. 



Aneurism is abnormal saccular dilatation of an artery 

 whereby is produced a pulsating tumour. A ^^ false aneu- 

 rism '' is a sac formed by condensed areolar tissue with a 

 free communication with the channel of an artery. True 

 aneurism generally constitutes one of the elements in a 

 case of atheroma, for the walls of the vessel, weakened 

 by degeneration, gradually yield to the blood pressure. 

 Cases of this condition have been recorded as affecting 

 the ox, but the absence of the usual causes, severe labour, 

 powerful action of the heart, and old age, prove material 

 preventives. '^ Spurious varicose aneurism ^' of the 

 remnant of the spermatic cord sometimes affects oxen, 

 as denoted by swelling of the scrotum, pulsation of the 

 part, and a peculiar bruit. Cases of this nature require 

 removal of the end of the cord with the clamps (See 

 ' Edinburgh Veterinary Review,' vol. i, p. 387). In the same 

 volume is mentioned a case of aneurism of the vertebral 



