40 AN ESSAY ON CH HO NIC PODOTROCIIOLITIS. 
never attains sufficient height to counteract that already developed 
in the trochlea. Admitting, however, that this effect may be pro- 
duced in cases of recent podotrocholitis, experience testifies that no 
confidence whatever can be placed in the efficacy of the seton 
where the disease is of long standing, and the consequences of in- 
flammation have already begun to manifest themselves. 
Opinions are divided" as to who it was that first applied the 
operation of neurotomy as a therapeutic agent against chronic po- 
dotrocholitis : some have attributed the priority to Coleman and 
Sewell, while Moorcroft claims it for himself. He says that he at 
first tried to open the pastern arteries, but, that that operation not 
having answered his wishes, he thought of cutting through the 
nerve which passes along the side of the metacarpus. Having 
remarked that the lameness reappeared after the lapse of a few 
weeks, he modified his proceedings, and, instead of a simple 
division, made a section, and cut off a quarter of an inch of the 
nervous cord. This latter mode of proceeding was, for a certain 
period, quite the fashion in England, as well as elsewhere, but it 
frequently happened that the lameness continued after the opera- 
tion had been performed : this was remedied by cutting both the 
pastern nerves with loss of substance. Most satisfactory results 
were thus obtained ; the horses ceased to limp : but still it not un- 
frequently happened that there was reason to regret that recourse 
had been had to this operation, on account of its inducing a total 
cessation of all nervous influence in the foot. Sewell consequently 
proposed that the operation should be performed on the posterior 
division beneath the articulation of the fetlock. 
The two last mentioned modes of proceeding are still practised ; 
and notwithstanding the length of time that has elapsed since neu- 
rotomy was first introduced into veterinary surgery as a means of 
curing chronic podotrocholitis, and the thousands of times that this 
operation has been performed, the most opposite opinions still 
prevail as to its value, and to the best method of performing it. 
The operation should be regarded in a physiological point of 
view, for thus alone can we learn properly how to appreciate it : 
hitherto physiology has been too much neglected. 
The consequence of neurotomy is an immediate cessation of the 
nervous action, and an interception of the sensation of those parts 
to which the divided nerves proceeded ; hence the pain which * 
prevailed there ceases. If the plantar nerves are cut through, the 
horse presses the foot that has been operated on firmly upon the 
ground, and, should the enervation be perfectly accomplished, that 
pressure is greater than it would naturally have been. Hence it 
follows that the compression and friction of the trochlea are no 
longer felt, although these parts still continue to be the seat of dis- 
