194 



MODERN HORSE MANAGEMENT 



[chap. 



Ether spray should be used before a trocar 

 and cannula are inserted, provided there is time. 



759. Anaesthesia by Local Injections. — The 

 second method, that of injecting cocaine, etc., 

 is used whenever the operation is near the 

 surface. The principle is that of numbing the 

 nerve before it gets to the part — that is, on the 

 side tovi'ards the brain or spinal cord. For this 

 reason a certain knowledge of neurology 

 (anatomy of the nerves) is required. P. 137 

 and 138(Z show the positions where injections 

 are made for common local operations. 



In neurectomy of the radial nerve, for in- 

 stance, the injection is made, ten to fifteen 

 minutes before the operation, over the radial 

 nerve on both sides of the leg, four to six inches 

 above the point of incision. 



In operations for straightening the tail the 

 injection is made at the root of the dock, on 

 both sides, ten to fifteen minutes previously. 

 Personally, I think the ether spray is better, as 

 it prevents the necessity for inserting a needle ; 

 therefore, there is less liability of missing the 

 nerve, and it is easy to discover when the part 

 is frozen. 



Freshly made solutions of cocaine hydro- 

 chloride must be used ; old solutions are of no 

 use. A 5 per cent, solution is generally used, 

 1 drachm of it for each injection ; 10 per cent, 

 cocaine should also be rubbed over the place to 

 be cut. In operating on the side of the body, the 

 injections should be made on the spinal cord 

 side in two or three places. For continued local 

 anaesthesia the doses must be repeated ; larger 

 doses must not be given at first. The action lasts 

 from twenty to thirty minutes. 



760. The best way is to procure cocaine 

 hydrochloride in 5-grain tablets ; one of these 

 added to nearly 1§ drachm of water would make 

 a 5 per cent, solution. Two tablets added to the 

 same amount of water would make a 10 per cent, 

 solution, for external application. For dogs, 

 always use a 5 per cent, solution. Over-doses 

 of cocaine produce a toxic effect. If serious, 

 strychnine must be given. 



761. Anxsthaine (Abbott Alkaloidal Com- 

 pany) is a valuable local anaesthetic, which is 

 sold in 1 oz. bottles. It has not the toxic effect 

 of cocaine, and produces local effects much more 

 quickly : in two to four minutes if applied ex- 

 ternally as a spray, and in four to six minutes 

 if injected hypodermically. A solution of anaes- 

 thaine is equivalent in strength to a 5 per cent, 

 solution of cocaine. 



Quinine and urea hydrochloride is also a new 

 local anaesthetic of great value. One grain of it 

 is equivalent to one grain of cocaine ; it is used 

 in 5 per cent, solutions. It has no toxic effects. 

 Over-doses produce no harm, except to induce 

 prolonged anaesthesia. The anaesthesia lasts much 

 longer, sometimes several hours or even days. 



Barker's solution of eucaine is also a valuable 



local anaesthetic, which has less toxic effects than 

 cocaine. Its strength is equivalent to 5 per cent, 

 solution cocaine. Holocaine and acoine are local 

 anaesthetics ; they are also antiseptic. Stovaine 

 and novocaine are used in 1 to 2 per cent, solu- 

 tions instead of cocaine. 



In giving cocaine to dogs, great care must be 

 exercised. One-tenth of a grain in 5 per cent. 

 solution is sufficient for hypodermic use on a 

 small dog, e.g. a small fox-terrier. This should 

 be repeated if there is no sign of cerebral nervous 

 excitement. 



762. The third method of anaesthetising, by 

 external applications of the fluids mentioned 

 above, is also used, but generally in conjunction 

 with hypodermic injections over the part to be 

 cut. 



This can be resorted to in order to relieve 

 pain from a bruise or a painful part. The drug 

 is rubbed in gently to hasten its absorption by 

 the skin. This method is used for operations on 

 the eye, such as removal of hay seed, cinder, 

 cataract, etc. 



A 1 per cent, solution of cocaine, using about 

 one-twentieth of a grain, i.e. 5 minims of the 

 solution, is dropped into the eye by means of a 

 dropper or clean fountain-pen filler. The surface 

 of the eye and a little beneath will be insensitive 

 vi'hen the pupil is much dilated, i.e. two or three 

 times its normal diameter. 



763. The fourth method, that of applying 

 electric impulses at a very high rate of speed, is 

 also practised in modern surgery considerably. 

 The Leduc apparatus produces a hundred electric 

 impulses to the second. The effect on the limb is 

 almost instantaneous lo»ss of feeling. 



764. Degree of Sensibility. — The sensibility 

 to pain in animals is less than that in human 

 beings, it being greatest in the horse and dog. 

 Next to them probably comes the guinea-pig. 

 The sensibility to pain in the cow, sheep and 

 pig is considerably less than that in a well-bred 

 horse or dog. The better the breeding the 

 greater the sensibility to pain. 



Humane Destruction 



765. The destruction of a suffering horse is 

 very often a matter of considerable difficulty, not 

 through want of means, but through want of the 

 knowledge of the method of doing it. If one 

 knows how a horse can be destroyed painlessly 

 by means of an ordinary penknife, he may be 

 able on many occasions to put a suffering horse 

 out of its misery. 



The most humane and the quickest and 

 cleanest way is that of shooting through the 

 brain. The layman who has not a thorough 

 knowledge of the anatomy of the skull should 

 shoot through the forehead into the lateral ven- 

 tricles of the brain. P. 138a shows the exact 

 position for the bullet to enter. Lines drawn 



