152 THE SURGICAL ANATOMY OF THE HORSE 



a general anesthetic. The upper hind limb should be drawn well forwards 

 and fixed to the upper fore limb by means of a side line or cross hobble. 

 Cross hobbles should also be applied to the affected limb and the corre- 

 sponding fore limb. The affected limb is then released from the ordinary 

 hobble and drawn well back, to permit which the rope connecting the 

 two cross hobbles has been loosely applied. 



The hock is now carefully palpated, and the position of the tendon 

 located. This frequently presents considerable difficulty, and it may be 

 necessary to cause the hock to be flexed and extended by an assistant. 

 An oblique incision is then made along the length of the tendon down- 

 wards and inwards, the incision passing through the skin and fascia 

 down to the tendon. The tendon is then drawn through the 

 cutaneous opening by means of a tenaculum and severed. In making 

 the cutaneous incision care must be taken to avoid injury to the 

 anterior root of the internal saphena vein. As a guide to the seat of 

 the incision, it may be remarked that the insertion of the tendon is in 

 line with the position of the chestnut. The writer has found the 

 success of this operation to be very variable, and after examination of a 

 large number of dissected hocks two conditions have been observed to 

 be commonly present which render the operation ineffective. In many 

 cases during the formation of the exostosis the tendon becomes displaced, 

 and will be found not to run over the exostosis at all. In a great per- 

 centage of the remaining cases with an existing large exostosis, since 

 the latter forms slowly, it was found that the tendon was accommodated 

 in a groove on the exostosis. Consequently in both these cases there 

 could be little, if any, abnormal pressure on the exostosis by the tendon. 



Dieckerhoff treated spavin by making an incision into the bursa ot 

 the cunean tendon. Other operators simply sever the tendon by press- 

 ing the blade through the skin and tendon, and tlien scrape the area 

 beneath. The object is similar to that in pyropuncturing the exostosis, 

 namely, to hasten the inflammatory process. The part is subsequently 

 blistered with biniodide of mercury ointment. 



