DISEASES OF BLOOD-VESSELS. I19 



The persistence of the pkigging and lameness must be met 

 by patience, the animal being turned into a small yard or pad- 

 dock where he can take gentle exercise and live well, until the 

 collateral vessels have had time to enlarge and carry on the 

 circulation. Three or four months will sometimes secure a 

 tolerable recovery. 



DILATATIONS OF THE ARTERIES. ANEURISMS. 



These are mostly seen in the horse among domestic animals, 

 and even in him much more rarely than in man. The causes 

 are generally severe strains in the vicinity of an artery, or over- 

 stretching of the vessel itself. They are also common in the 

 mesenteric arteries of horses from the presence of immature 

 worms {Sclerostomum Equinum) in the circulating blood. In- 

 juries to the walls of the vessels are much less liable to be fol- 

 lowed by aneurism than in man, because of the greater plas- 

 ticity of the blood, and the speedy formation of a covering of 

 coagulable lymph. They are soft, fluctuating, pulsating tumours, 

 effaceable by pressure, but reappearing at once. Being usually 

 situated internally, treatment can rarely be adopted. But wher 

 superficial, compression has been most successful alike in the 

 horse and dog. It is needless to recount the many other 

 modes of treatment for such an unusual affection. 



DISEASES OF VEINS. 

 WOUNDS OF VEINS. 



These give rise to the escape of a dark red blood in a steady 

 stream. This is commonly to be arrested by pinning up the 

 lips of the wound evenly, taking hold of each by one-eighth 

 inch and tying them together by a little tow, twisted round the 

 two ends of the pin in the form of the figure 8. Or several 

 pins may be placed near each other and the tow twisted round 

 them and from pin to pin in the same manner. Veins may be 

 tied, but this risks the occurrence of dropsy unless you know 

 \hat there is a free circulation by other collateral trunks. They 



