148 CHAPTER 17. 



their administration. Though the bowels cannot always be acted on, 

 the kidneys are very easily affected. 



The diuretics in common use are resin, turpentine, etherous substances, 

 and small doses of nitrate or acetate of potash or other saline matters. 

 The latter, however, if given in large quantities, are excreted by the 

 bowels. 



Diuretics, though acting locally on the kidneys, affect the whole sys- 

 tem, because the secretions which they induce are drawn from the system 

 generally, as explained under the head of purgatives. Hence they are 

 given in fevers with the view of removing from the blood those delete- 

 rious matters which in such cases always accumulate in the system from 

 suspension of the secretory powers. They are also employed to remove 

 from the body excess of fluids or " humours," as they are popularly 

 called, as in cases of swelled legs. 



The kidneys themselves are rarely affected primarily. Affections of 

 the urine generally arise from derangement of the digestive organs. If 

 the kidneys get into a chronic state of torpidity the cause will probably 

 be found in want of tone of the system. The true remedy in all such 

 cases lies in good feeding, air, exercise, and proper attention to stable 

 duties rather than in the administration of diuretics. 



Diuretic balls are generally made of two drachms each of resin arid 

 nitre with one drachm of Venice turpentine, mixed in a mass with soft 

 soap and linseed meal. 



293. Diaphoretics. 



The skin is the channel through which the system excretes a large, 

 though variable, amount of refuse fluid matters, holding in solution 

 various salts and effete organic matters. It has been estimated that as 

 large an amount of matter is passed off through the skin of a horse in 

 high condition and active exercise as by all the other excretory organs. 

 Hence exercise, occasionally at least sufficient to produce a good sweat, is 

 essential to health. 



During those diseases in which the functions of the kidneys, lungs, or 

 bowels are more or less disturbed, and when exercise cannot be taken, it 

 is often of great importance to maintain, and if possible increase, the 

 action of the skin, in order to prevent the blood from being poisoned by 

 the accumulation of deleterious matters in it. 



Diaphoretics are medicines used to increase the action of the skin by 

 stimulating the cutaneous glands and vessels. They answer well and are 

 frequently used in the human subject; but in the horse, partly on 

 account of the hair with which the skin is covered, and partly on account 

 of the tendency of the medicine to be passed off by the kidneys and 

 bowels, they are not available. The best practical method of causing 

 diaphoresis in the horse is to administer diluents in large quantities, 

 then to apply friction over the body, and to keep the animal well covered 

 with double clothing in a warm atmosphere. A Turkish bath, if avail- 

 able, but this is rarely the case, will produce the desired effect. 



