478 VARIX, OR BLOOD SPAVIN. 



solution of chloride of zinc, two scruples to the pint of 

 water. 



EXTERNAL TUMOURS. 



Sitfast is a thickening of the cuticle, produced by the 

 friction of the saddle. It is best removed by the application 

 of blistering ointment, rubbed in upon the excrescence, and 

 an inch all round it. This is to be repeated daily till the 

 sitfast falls off, which it will do after a few applications. 

 The sore left is to be dabbed thrice daily with the weaker 

 solution of chloride of zinc. 



Induration of the elbow is sometimes observed, and of car- 

 tilaginous hardness, occasioned by the horse lying with his 

 fore legs doubled under him, so that his elbow rests on the 

 heel of the shoe, particularly when worn long or with 

 calkens. It would be useless to attempt a cure without 

 removing the cause : that removed, by taking down the 

 calkens and shortening the heels, the enlargement might be 

 dissected out. 



CHAPTER XV. 



OF ENCYSTED SWELLINGS. 

 VARIX, OR BLOOD SPAVIN. 



A DISEASED enlargement of the coats of the veins is termed 

 varix, but which is not a common affection of the horse, as 

 his superficial order is comparatively small, and not sub- 

 jected to such artificial pressure as our own. The only 

 instance usual in veterinary surgery is that termed blood 

 spavin ; which presents certainly something like a varicosed 

 enlargement of the superficial vein passing over the hock ; 

 this is the consequence of the pressure of a distended cap- 

 sule, which is called bog spavin. The dilatation, being 

 situated immediately below the bog spavin, is caused by 

 obstruction to the passage of the blood, and a consequent 

 extension of the coats of the vein. Usually, therefore, the 

 dilated capsule is the part to be attended to ; but when the 

 vein itself becomes so much enlarged as, by its own pressure, 



