106 DISEASES OF THE HORSE’S FOOT 
symptoms of lameness still persist after section of the nerve. 
In many cases this has been traced to the existence of an 
abnormal nerve branch. In the higher operation this is 
not so likely to be met with. That it may occur, however, 
is shown by the following interesting case related by Harold 
Sessions, F.R.C.V.S. :* 
‘In June of 1898 I saw a hunter suffering from navicular 
disease. After carefully examining the leg, I advised the 
owner to have the operation of neurectomy performed upon 
him. This he decided to do, and the horse was sent to me 
about the beginning of July. 
Fic. 62.—Dissectep ExternaL METACARPAL NERVE AND BRANCHES. 
a, Metacarpal; 6, anterior plantar; c, extra branch (probably from the 
internal metacarpal), conveying sensation after division of the external 
metacarpal. 
‘The operation was performed in the ordinary way, with- 
out any difficulty whatever. The wounds healed nicely, 
but the horse still continued to go lame. Careful examina- 
tion showed that there was still sensation on the outside of 
the foot. Thinking that possibly there might be two 
external metacarpal nerves, the horse was again cast, the 
operation being performed slightly lower down. Only the 
main branch of the external metacarpal nerve could be 
found. A piece of this was taken out, and the horse let up. 
On examination, sensation was still found in the posterior 
part of the outside of the foot. It was very evident that 
there was some abnormal distribution of the nerve, as 
sensation was still being conveyed to that part of the foot. 
‘As the horse was absolutely useless, and would have to 
* Journal of Comparative Pathology and Therapeutics, vol. xii., 
p. 343. 
