PRINCIPLES OF VETERINARY SURGERY 251 



about one dram of a io% solution in the tail preparatory to 

 the operation of caudal myotomy. But this horse plunged 

 violently in the stocks and resisted every attempt to con- 

 tine him, and probably died from traumatic syncope or re- 

 flex syncope. The post-mortem revealed no lesion to which 

 the death could be traced. 



Posology and Administration. — The toxicity of cocaine 

 or any other potent local anaesthetic must always be kept 

 prominently in mind. The reckless injection of these 

 medicaments is often disastrous, although the lower ani- 

 mals are much more difficult to kill with them than the 

 human family, certain individuals of which seem to possess 

 manifest sensibility to their systemic actions. These 

 idiosyncrasies do not exist in animals to any appreciable 

 extent. Deaths from cocaine are rare in the horse, and 

 they occur in the dog only when the dose has been exces- 

 sive. Five grains should be the maximum dose for the 

 horse and one-eighth to one-fourth grain for the dog. In 

 the latter animal there is little demand for its use, owing 

 to the facility with which operations can ht executed with- 

 out anaesthesia, as well as the facility with which the gen- 

 eral anaesthetic can be administered. 



The five per cent aqueous solution of cocaine hydro- 

 chlorate is the most appropriate local anassthetic for gen- 

 eral uses in the veterinary subjects. When only very small 

 areas are to be anaesthetized, the ten per cent solution may 

 be used, but for general use this is too concentrated, and is 

 positively harmful in any considerable quantity. With the 

 five per cent concentration one dram of the solution (three 

 grains) can be injected with impunity. This quantity of the 

 solution is sufficient for the large majority of indications. 

 When a larger surface is to be anaesthetized^ an additional 

 half dram can be safely given, but the better method is to 

 dilute the solution to 4%, 3% or 2% when larger quantities 

 are required. 



