76 



LAMENESS OF THE HORSE 



casting harness. The common cause of paralysis or paresis of 

 this nerve in cases such as one observes in country practice, is 

 bruises from the collar in colts that are put to heavy farm work 

 or whore ill fitting collars are used. 



Symptomatology. — With partial or complete suspension of 

 function of the suprascapular nerve there results enervation 

 of the supraspinatus and infraspinatus muscles. Since these 

 muscles act as external lateral ligaments 

 of the scapulohumeral joint, when they 

 are incapacitated, there naturally fol- 

 lows more or less abduction of the 

 shoulder Avhen weight is borne. 



In extreme cases, as soon a.!, the ailing 

 animal is caused to support w^eight with 

 the affected member, the joint is sud- 

 denly thrown outw^ard in a manner that 

 the average layman at once concludes 

 that there must be scapulohumeral luxa- 

 tion, and the veterinarian receives a call 

 to see a case wherein the "shoulder is 

 out of place." There exists, however, no 

 luxation in such cases. 



If serious injury is done the nerve so 

 that it undergoes degenerative changes, 

 there will result atrophy of the muscles 

 that derive their nerve supply from the 

 suprascapular nerve. 



Treatment. — During the hrst few days 

 following injuries wiiich result in this 

 form of paralysis, it is Avell to keep the subject inactive, and 

 if much inflammation of the injured structures contiguous to 

 the nerve exists, the application of cold packs is beneficial. 

 Later, as soon as acute inflammation has subsided, vesication 

 of a liberal area around the anteroexternal part of the scapu- 

 lohumeral joint and over the course of the suprascapular nerve, 

 W'ill stimulate recovery in favorable cases. As a rule, in mild 

 cases, the subject is in a condition to return to Avork in two or 

 three weeks. 



Fig. 7 — Paralysis of the 

 .suprascapular nerve of 

 the left shoulder. 



