112 USES OF CATHARTICS 



apt to cause vomiting, or, if retained, to purge with undue 

 violence. 



Pigs are affected by cathartics much in the same way as 

 men and dogs, and are best physicked by administering 

 three or four ounces of Epsom salt dissolved in water, or a 

 like amount of linseed or castor oil. 



The uses of purgatives are numerous. Few medicines are 

 applied to so many important purposes. 



(1) They empty the alimentary canal of undigested food, 

 faeces, bile, unabsorbed poisons, and worms. Sweeping away 

 partially digested food, they diminish the amount of blood- 

 making materials, and thus diminish plethora and obesity. 

 In horses fully two-thirds of the fluid ingesta, under ordi- 

 nary circumstances, is removed by the bowels, and this 

 large amount is greatly increased when physic is given. 

 They remove noxious gases and fluids, micro-organisms, 

 ptomaines, and other intestinal toxic matters which are the 

 causes of dyspepsia, colic, and diarrhoea ; and which, more- 

 over, secondarily or reflexly produce nervous depression, 

 and other serious effects on the system. 



Constipation is usually dependent in great part on deficient 

 peristalsis, and hence, when of frequent occurrence, is often 

 advantageously combated by conjoining a little nux vomica 

 with the cathartic. When the general vigour of the patient 

 is defective, the aperient may be conjoined with iron or 

 arsenic ; and where there is venous congestion, with 

 digitalis or belladonna. Horses restricted to dry food are 

 frequently affected with constipation, and in such cases the 

 diet should be varied with an occasional mash, a little lin- 

 seed cake or green food, while water ad libitum should be 

 allowed at least four times daily. The bulky and com- 

 paratively indigestible nature of the horse's food induces 

 copious alvine evacuations, which are passed usually at 

 intervals of four or five hours. Impaired intestinal action, 

 or obstruction, hindering or arresting these frequent evacua- 

 tions, causes more serious and rapidly fatal results in horses 

 than in dogs, or ruminants, in which the bowels naturally 

 act less frequently. Torpidity or obstruction which has 

 resisted ordinary treatment is now usually relieved even 

 in horses by the hypodermic injection of a grain of eserine 



