76 DISEASES OF THE HORSE’S FOOT 
much so, that the opinion as to navicular disease was con- 
firmed, and neurectomy was performed. Immediately after 
this operation there was no lameness whatever. 
The same author also reports numerous cases among 
horses and cattle, dogs and cats, pointing out the toxic 
properties of the drug. The symptoms following an over- 
dose are interesting enough to relate here, and I select 
the following case of Professor Hobday’s as being fairly 
typical : * 
CaszE IV.—Cart gelding. Free clinique; navicular 
disease. Injected subcutaneously over the metacarpal 
nerves on each side 6 grains of cocaine in aqueous solution. 
During the operation the animal manifested no signs of 
pain whatever, not even when the nerve was cut. This 
animal received altogether 12 grains of cocaine (3 grains 
were given on either side first, then fifteen minutes 
afterwards the same dose repeated). The effect was 
manifested on the system in ten minutes after the 
second injection by clonic spasms of the muscles of the 
limbs (the legs being involuntarily jerked backwards and 
forwards at intervals of about twenty seconds), which 
materially interfered with the performance of the opera- 
tion. The animal was also continually moving the jaws, 
and was very sensitive to sounds, moving the ears back- 
- wards and forwards. This hyperesthesia, as evinced by 
the movement of the ears, lasted for some considerable 
‘time after the animal had been allowed to get up. 
Cocaine hydrochlorate solutions, if intended to be kept 
for any length of time, should have added to them when 
freshly made ,3, part of boric acid in order to preserve 
them. Even then they are liable to spoil, and should, for 
subcutaneous injection, be made up just before needed 
for use. 
* Toe. cit. 
