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 3 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 neces- 

 sary 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 position, 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. 



Anaesthesia 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 anaesthesia than equally strong 

 cold solutions. 



4. In the sale of horses cocaine injections conceal fraud. 



