64 PEEPUTIAL CALCULI. 



discharged urine, and there are usually symptoms of irrita- 

 tion of the bladder. Animals affected with this disease can- 

 not thrive, and attract special attention from making frequent 

 attempts to discharge urine. In the horse, the deposit con- 

 sists of mucus, carbonate of lime, and magnesia, whereas 

 in pigs it is composed of mucus, crystals of ammonia, 

 and phosphate of magnesia. 



The treatment of gravel may necessitate the operation of 

 urethrotomy, and washing or scooping out of the earthy 

 sediment from the bladder. In all recent cases, lithontryp- 

 tics, viz., internal remedies to dissolve the deposit, should be 

 used, such as hydrochloric acid. Horses should be allowed 

 demulcent drinks in abundance, so as to relieve the local 

 irritation. Such demulcent draughts may consist of decoc- 

 tions of linseed or simple mucilage. 



