639 



CHAPTER XXIX. 



Administration op Medicines. 

 different methods and respective proportions of medicines by 



THE MOUTH BY THE RECTUM BY SUBCUTANEOUS (hYPODBRMIC) 



INJECTION BY THE WINDPIPE BY PUNCTURE INTO THE LARGE 



INTESTINE BY A VEIN BY THE SKIN BY THE MUCOUS MEMBRANE 



AND CORNEA. 



Different Methods and Respective Proportions of 

 Medicines. 



In order to produce a general effect, medicines are usually given 

 to horses by the mouth, rectum, subcutaneous tissue (tissue im- 

 mediately below the skin), and windpipe; and occasionally by a 

 vein, and by puncturing the large intestine. As a rule, medicines 

 are administered locally, by application to the skin, mucous mem- 

 brane, cornea, and subcutan.eously. 



The effect of the active principle of a medicine in solution, when 

 given by the rectum, is two or three times ; when given sub- 

 cutaneo'usly, seven or eight times ; and when given by the wind- 

 pipe, from fifteen to twenty times greater thfin whC'n given by 

 the mouth. Consequently, the respective doses should be pro- 

 portionately diminished. We may assume that the rapidity of 

 absorption is approximately proportionate to the effect produced; 

 supposing that the solution is at the same temperature in all these 

 cases. Cold solutions are absorbed much more slowly than warm 

 ones, the temperature of which should not be much above blood 

 heat, say not over 105° F. 



By the Mouth. 



This is the usual way of administering medicines to horses, 

 because it is simple, easy of execution as a rule, and because it is 

 the best method for the absorption of oily and solid agents. Al- 

 though the mucous membrane has little power of absorbing oil. 



