74 DISEASES OF THE HORSE’S FOOT 
Where, though we may have suspected the foot, we have 
not been able to definitely assure ourselves that there the 
mischief is to be found, a further method of examination 
presents itself—namely, subcutaneous injections of cocaine 
along the course of the plantar nerves. 
The salt of cocaine used is the hydrochlorate, 2} grains 
for a pony, 4 grains for a medium-sized animal, and 
6 grains for a large horse. A solution of this is made in 
boiled water (about 8 drams), and injected at the seat of 
the lower operation of neurectomy. 
It is advisable to first render aseptic the seat of opera- 
tion, and to sterilize both the needle and the syringe by 
boiling. A suitable point to choose for the injection is 
exactly over the upper border of the lateral faces of the 
two sesamoids, the needle being introduced behind the cord 
formed by the nerve and accompanying vessels, and parallel 
with it. 
It is possible that the vein or the artery may be wounded, 
but such accident is of little importance. All that is 
necessary in that case is to partly withdraw the needle and 
again insert it. It is advisable to use a twitch. 
When the needle is in positien, the injection should be 
made slowly, and at the same time the point of the needle 
should be made to describe a semicircular sweep, so as 
to spread the solution over as wide an area as is possible. 
Anesthesia ensues in from six to twenty minutes, and if 
the cause of the lameness is below the point of injection 
the animal moves sound. 
Regarding this method of diagnosis, Professor Udriski 
of Bucharest, after a series of trials, sums up as follows: 
1. For the diagnosis of lameness cocaine injections are 
of very considerable value. 
2. These injections should be made along the course of 
the nerves. 
3. Solutions heated to 40° or 50° C. produced quicker, 
deeper, and longer anesthesia than equally strong 
cold solutions. 
4. In the sale of horses cocaine injections conceal fraud. 
