THE NERVE OPERATION. 3G1 



On the Nerve Oj^eration. 



This operation was discovered by Mr. Sewell, Assistant Pro- 

 fessor of the Veterinary College, and first communicated by liim 

 to the Royal Society.* 



* " This operation is likewise known by the different appellations of nerving, 

 unnervinfi, and neurotomy, and consists in the division and excision of a por- 

 tion of the metacarpal or plantar nerves, thus destroying sensation in the 

 foot. The nerves which arise from the spinal column have been found by 

 the discoveries of Sir Charles Bell and others to have a double origin, one 

 from the back, or, in brutes, upper part of the cord by a number of filaments 

 which coalesce, and then form a sort of knot called a ganglion ; the other 

 portion rises in a somewhat similar manner from the under or anterior part 

 of the spinal column, and joins the other without forming any ganglion. Thus, 

 though the nerves are apparently united, the filaments are yet distinct, each 

 having its neurilema or nervous covering. The former is the nerve which 

 communicates sensation; the latter that which conveys the power of motion, 

 and a part is endowed mostly with sensation or with motion, according as the 

 filaments of the former or of the latter predominate. It is a law of nature 

 that no structure nor fimction is ever supplied in a situation where it cannot 

 be brought into operation ; consequently, as the motion of the limbs is effected 

 by means of contraction of the muscles, and there are no muscles below the 

 knee, there are therefore no motor nerves below the knee ; sensation alone 

 is cut off; and pain being the cause of lameness, the effect ceases with the 

 removal of tlie cause. 



" The honour of the discovery of this important operation belongs to Pro- 

 fessor Sewell. We are told that Mr. Moorcroft and others had previously 

 pertbrmed it, but, be this as it may, they never publicly introduced or recom- 

 mended it, and could therefore have no confidence in its merits. It was 

 Mr. Sewell, and he alone, who first generally practised and recommended it 

 for incurable foot lameness. Like most other discoveries it has met with 

 assailants, from all quarters, both in the profession and out of it ; and not a 

 few of them have been owing to the careless and indiscriminate manner in 

 which many practitioners have performed it, heedless altogether as to the 

 nature and history of the case, or of the work the horse was afterwards to 

 perform. This was the fact more particularly during the early days of the 

 operation. There were groggy horses all over the country far more than 

 there are at present, particularly in coaches. Many of these had been lame 

 for years, and were at once submitted to the operation, and soon afterwards 

 resumed their work at a quick pace on the road ; the consequence was, in a 

 number of cases, the inflammation that, perhaps, had never subsided, became 

 vastly increased by the renewal of severe labour and the unusual boldness, 

 with which the animal put his foot to the ground and bore his weight upon it; 

 swelling and morbid fomentations succeeded, or, in other instances, suppura- 

 tion supervened, the hoof sloughed off, and the animal was obliged to be shot. 



" In other cases, where lameness has existed for years, and ulceration had 

 been going on to a great extent, and the flexor sinew had become attenuated, 

 the horse with the removal of pain and lameness, no longer having these 

 often useful monitors to tell him of the consequences, treads boldly on these 

 diseased parts, and the thin sinew which, perhaps, never would have given 

 way as long as the foot possessed sensation, suddenly snaps like a thread, 

 and the horse presents the sad aspect of walking entirely on his heels, the 

 toe being elevated from the groun<l. Notwithstanding these deplorable re- 

 sults, which the practitioner should always bear in mind when he recommends 

 the operation, in spite of their very frequent occurrence in times past, and 

 their occasional recurrence at the present day, the operation still continues 

 to be successfully practised, when performed with discretion, and proper care 



