DISEASES OF HORSES 235 



the greater relative length of the bony levers in the human formation 

 may constitute a cause of the difference. Among the predisposing 

 causes in animals may be enumerated caries of articular surfaces, 

 articular abscesses, excessive dropsical conditions, degenerative soft- 

 ening of the ligaments, and any excessive laxity of the soft structures. 



Treatment. The treatment of luxations must, of course, be sim- 

 ilar to that of fractures. Reduction, naturally, will be the first indi- 

 cation in both cases, and the retention of the replaced parts must 

 follow. The reduction involves the same steps of extension and 

 counter extension, performed in the same manner, with the patient 

 subdued by anesthetics. 



The difference between the reduction of a dislocation and that 

 of a fracture consists in the fact that in the former the object is 

 simply to restore the bones to their true normal position, with each 

 articular surface in exact contact with its companion surface, the 

 apparatus necessary afterwards to keep them in situ being similar to 

 that which is employed in fracture cases, and which will usually re- 

 quire to be retained for a period of from forty to fifty days, if not 

 longer, before the ruptured retaining ligaments are sufficiently firm to 

 be trusted to perform their office unassisted. A variety of manipula- 

 tions are to be employed by the surgeon, consisting in pushing, pull- 

 ing, pressing, rotating, and indeed whatever movement may be nec- 

 essary, until the bones are forced into such relative positions that the 

 muscular contraction, operating in just the right directions, pulls the 

 opposite matched ends together in true coaptation a head into a cav- 

 ity, an articular eminence into a trochlea, as the case may be. The 

 setting is accompanied by a peculiar snapping sound, audible and 

 significant, as well as a visible return of the surface to its normal 

 symmetry. 



Special Dislocations. While all the articulations of the body 

 are liable to this form of injury, there are three in the large animals 

 which may claim a special consideration, viz. : 



DISEASES OP MUSCLES AND TENDONS. 



Sprains. This term expresses a more or less complete lacera- 

 tion or yielding of the fibers of the muscles, tendons, or the sheaths 

 surrounding and supporting them. The usual cause of a sprain is 

 external violence, such as a fall or a powerful exertion of strength, 

 with following symptoms of soreness, heat, swelling, and a suspen- 

 sion of function. Their termination varies from simple resolution 

 to suppuration, and commonly fibrinous exudation difficult to re- 

 move. None of the muscles or tendons of the body are exempt from 

 liability to this lesion, though naturally from their uses and the ex- 

 posure of their situation the extremities are more liable than other 

 regions to become their seat. The nature of the prognosis will be 

 determined by a consideration of the seat of the injury and the com- 

 plications likely to arise. 



Treatment. The treatment will resolve itself into the routine of 

 local applications, including warm fomentations, stimulating lini- 

 ments, counterirritation by blistering, and in some cases even firing. 

 Rest, in the stable or in a box stall, will be of advantage by promoting 



