TIME OF ADMINISTKAXION 13 



contains large amounts of food in the rumen and abomasum, 

 while the impervious, poorly vascular and skin-like gastric 

 mucous membrane renders absorption feeble and imperfect 

 and enforces a comparatively larger dosage than is proper 

 for horses of greater weight. Ruminants are also generally 

 insusceptible to emetics. The skin and kidneys of rnmi- 

 • aants are still less active than is the case in horses. 



ACTION OF DKUGS ON DOGS AND PIGS AS COMPARED WITH THAT ON 

 OTHER ANIMALS. 



The action of medicine on dogs and pigs is similar in 

 kind to that observed in man, but the former animals are less 

 sensitive to drugs as a rule, since the dose suitable for a 

 man weighing 150 pounds is appropriate for a dog of 40 

 pounds weight. As exceptions to this rule, we find that dogs 

 will not bear the human dose of calomel, oil of turpentine, 

 or strychnine. Tn fact, the ordinary tonic dose of strych- 

 nine (gr. ^L) for man will throw a medium-sized dog into 

 convulsions, and may kill a small animal, notwithstand- 

 ing that this amount is recommended as a suitable canine 

 dose in veterinary text books. 



Contrariwise, the dog is comparatively insensitive to 

 many drugs powerfully influencing man, — notably aloes, 

 oolocynth and rhubarb. Most cathartics act more quickly 

 on dogs than is the case with the other domestic animals, 

 but saline purgatives are less appropriate in often causing 

 vomiting, and because of their bulk. 



Time of Administration. 



This matter has been alluded to in speaking of the 

 absorption of drugs. Medicines readily undergoing decom- 

 position in the presence of other substances, as iodine and 

 hydriodic acid, should be given on an empty stomach ; and 

 likewise all drugs, when a speedy action is desired. Irrit- 

 ants should be administered on a full stomach. 



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