714 HYPODERMIC ADMINISTRATION 



collapse, paroxysms of acute pain, and con- 

 vulsions. 



(2) Where it is desired that the drug shall act 

 promptly and directly on the diseased part, as in 

 neuralgia, rheumatic pains, and mammitis in cows. 



(3) Where local and general effects are desired to be 

 conjoined, as in reflex spasms. 



(4) Where administration by the mouth is difficult, 

 impossible, or inadvisable. 



The drugs thus used should be in neutral, non-irritant, well 

 diluted solution, and preferably dissolved in water or in 

 vegetable oil. Alcohol, chloroform, and glycerin, though 

 often employed, are objectionable, and concentrated solu- 

 tions should be avoided as they cause pain and are less 

 rapidly absorbed. The quantity injected at one point 

 should seldom exceed two drachms ; when larger quantities 

 must be administered, injections should be made at different 

 points of the skin. Many veterinarians use morphine, 

 atropine, ergotin, eserine, arecoline, and other active drugs 

 hypodermically for arresting or controlling the spasms of 

 colic and chronic cough, the sharp twinges of rheumatism, 

 the inflammatory pain of enteritis, pleurisy, and laminitis, 

 as well as for combating the effects of poisons. By this 

 method are administered pilocarpine, apomorphine, adren- 

 alin, atoxyl, sodium cacodylate, caffeine, cocaine and other 

 local anaesthetics, sterilised gelatin, and the various organic 

 and artificial sera. Where local pain is to be coun- 

 teracted, the injection may be made more deeply near 

 the affected spot, or over the nerve which is believed 

 to be conveying the disordered impression. With active 

 agents it is unwise, without careful trial, to inject sub- 

 cutaneously more than one-fourth of the dose which would 

 be given by the mouth. Strychnine is too active, and quinine 

 is too irritant for safe administration by this method, but 

 there is less risk in veterinary than in human patients of 

 subsequent local irritation. 



The hypodermic syringe has a glass barrel with metal 

 mounts, a hollow needle fitted to the nozzle, and an asbestos 

 piston. It is essential that every part of the syringe be 

 aseptic, and the needle sharp. Hypodermic injection is 



