HABITS AND IDIOSYNCRASIES 37 



acquiring greater power for the detention, modification, 

 destruction or excretion of the drug, while frequently the 

 tissues, by repeated contact, become progressively accus- 

 tomed to its influence, and more or less resistant. 



Individual Idiosyncrasies, which in the human subject 

 render some poisons almost innocuous, and some simple 

 medicines deadly poisons, are less frequent and notable 

 among the lower animals. Those of most frequent occur- 

 rence among veterinary patients are either an increased or 

 a diminished susceptibility to the action of purgatives and 

 diuretics. Most medicines act with greater certainty and 

 effect upon weU-bred animals, whether horses or dogs, 

 than upon coarsely-bred mongrels. The prescription even 

 of a blister or a colic draught demands consideration of the 

 temperament, breeding, and condition of the patient. 



Diseases modify the action of many medicines. Altered 

 structure and functions, and increased temperature occur- 

 ring in most serious disorders are important modifying 

 factors. A congested or inflammatory condition of the 

 alimentary canal, or even an overloaded stomach, retards 

 absorption, and the consequent activity of medicines given 

 by the mouth. Acute fever, on account of increased arterial 

 pressure, is also unfavourable to absorption. When ex- 

 cretion is hindered, medicines, however, are usually retained 

 longer in the system, and some accordingly act more power- 

 fully. Conversely, when excretion is active, as in diuresis, 

 diabetes, or diarrhoea, such medicines as opium, belladonna, 

 and alcohol, being rapidly got rid of, do not manifest their 

 full activity. Influenza, low fevers, and any considerable 

 inflammation of mucous or cutaneous surfaces, withstand 

 reducing remedies badly, and require for their successful 

 treatment the early exhibition of restoratives, tonics, and 

 stimulants. Even the comparatively slight and temporary 

 requirements for the changing of the coat render horses in 

 spring and autumn notably less enduring and less able to 

 stand lowering treatment. Full doses of sedative medicines 

 induce less depression in acute inflammation than in health ; 

 large quantities of opium and chloral hydrate have compara- 

 tively slight effect in tetanus, enteritis, or other painful 

 disease ; while excessive doses of purgatives and stimulants 



