SETONING 93 



When lameness from such lesions persists despite rest and 

 superficial applications, setons are indicated and often ac- 

 complish the desired effect promptly. In muscular atrophy 

 supervening injuries to motor nerves, setons applied directly 

 over the wasted muscles will stimulate the regenerative proc- 

 ess, but only after the nerve itself has already regenerated. 

 In atrophy too much must not be expected of setons before 

 the function of the injured nerve has been restored, because 

 muscle regeneration is incapable of proceeding in the ab- 

 sence of the nerve impulse to stimulate its contractions. 

 But when the innervation has been re-established and the 

 muscle elements become stimulated to renewed activity, the 

 application of setons will materially promote the regenera- 

 tive process, and thus soon restore the wasted region to its 

 former condition. In the treatment of "shoulder sweeny," — 

 a typical example of atrophy from suspended innervation, — 

 seton after seton may be inserted without effect and the case 

 may finally be abandoned as incurable, when suddenly at a 

 given time it rs noticed that the region is filling up. At this 

 moment, which in fact, corresponds to the time that the 

 function has been restored,, setons will hasten the growth of 

 the muscle fibers. If the nerve is injured beyond repair the 

 atrophy will be permanent in spite of all treatment. In the 

 atrophy of azoturia an analogous situation is encountered. 

 The muscles waste rapidly and remain atrophied in spite of 

 all treatment as long as the nerves remain inactive, but fin- 

 ally, after months, they begin to regenerate and are soon re- 

 stored to their normal size. It is during this period of spon- 

 taneous regeneration that the seton is an effectual auxiliary. 

 In other words, setons are incapable of regenerating par- 

 alyzed nerves, but will promote the restoration of the wasted 

 muscles when the nerve impulses are resumed. That is to 

 say they promote muscle regeneration in atrophy. 



In the treatment of navicular disease the frog seton was 

 once a standard treatment, but owing to the poor results gen- 

 erally obtained, its use has been discarded by the modern 

 veterinarian. The results once attributed to this method of 

 treatment were probably always over-estimated, and it is 

 quite evident that errors in diagnosis have been the means of 

 unwittingly placing credit where it was not due. 



Setons also very frequently serve a useful purpose in the 

 treatment of fistulae (fistulse of the withers, poll-evil, quittor, 

 etc.) where the drainage tract is certain to cicatrize before 

 the necrotic tissue has separated and sloughed out. It often 

 happens that fistulous diseases are submitted to operation 



