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 :* 



Case 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 after- 

 wards 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 operation. The animal was also 

 continually moving the jaws, and was very sensitive to 

 sounds, moving the ears backwards 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 1/200 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. 



* hoc. cit. 



