NEUROTOMY 131 



the tumefaction accentuates and soon becomes enormous. 

 The fetlock is held in volar flexion, in its normal position, or 

 in aggravated dorsal flexion, according to the amount of pain 

 and the strength of the supporting tendons. If there is much 

 pain the volar position of the fetlock will delay the eventual 

 breaking away of the tendon attachments, while on the other 

 hand if the pain is not much in evidence the dissolution will 

 rapidly follow under the strain of ordinary work, and soon 

 render the patient useless. 



After the higher neurotomies, median and tibial, the 

 sesamoidean ligaments are often the sole seat of dissolution. 

 This form is manifested by marked dorsal flexion, swelling 

 of the region and early ruination of the subject. In these 

 events, the occurrence usually follows soon after operation, 

 generally when the horse is first given severe work. 



The following is a fair example of break-down after tibial 

 neurotomy: A draft horse affected with chronic sesamoiditis 

 of one year's duration supervening thecal abscess, was un- 

 nerved above the hock. Twenty days later he was put to 

 light work and seemed to progress favorably. On the thir- 

 teenth day, while working in a tram hitched to a heavily 

 laden wagon, the fetlock suddenly gave way and descended 

 to the ground. The horse was killed, and post-mortem dis- 

 section showed that the suspensory ligament, the x, y and v 

 ligament and the perforatus tendon were wrenched from 

 their attachment. 



The delayed sequelae are preventable to a certain extent 

 by giving the unnerved horse a less arduous occupation, by 

 the application of supporting bandages and by shoeing with 

 high heel calks. The acute forms are not preventable, as 

 they occur under the strain incident to supporting the weight 

 of the body. 



The cause of break-down of the acute variety is always 

 traceable to the indiscreet application of neurotomy to acute 

 inflammatory conditions, or else to lameness accompanied 

 with deformed, weak hoofs. In the chronic variety it is gener- 

 ally the result of continued violent work without adequate 

 efforts to protect the weakened organs. 



These accidents are due strictly to the mechanical vio- 

 lence (supporting weight, trotting, pulling, etc.) inflicted 

 upon structures too weak or too diseased to withstandthe 

 strain. They have sometimes been attributed to mysterious 

 trophic disturbances incident to the removal of the innerva- 

 tion, but this theory is not well founded, because the opera- 

 tion, when performed upon strictly €ound horses, is never fol- 



