DISEASES OF THE URINARY ORGANS. 211 



rendered torpid or paralyzed by over-distension, severe par- 

 turition or otherwise. The animal strains violently, and a red, 

 tumid, rounded mass appears from between the lips of the 

 vulva. On examinins: its surface near the neck the two orifices 

 of the ureters may be detected with the urine oozing from them 

 in drops. 



Treatment. — Wash with milk-warm water containing lauda- 

 num, and return, pressing the centre of the mass inward so as 

 to correct the eversion. The main difficulty will be met in 

 returning it through the contracted neck of the bladder, and if 

 the eversion has lasted long enough to determine inflammation 

 and softening, great care will be requisite to avoid tearing the 

 coats. Should straming be so violent as to threaten renewal of 

 the eversion, a truss may be applied as advised for eversion of 

 the womb. 



URINARY CALCULI AND GRAVEL. STONE. 



These vary in chemical composition with the genus of animal 

 and especially with the nature of the food. In herbivora the 

 urine normally contains a large amount of the carbonates of 

 lime and magnesia, and of oxalate of lime, a small quantity of 

 silica, sulphate and phosphate of lime, ammonia-magnesian 

 phosphate, hippuric acid, and sometimes uric acid, besides the 

 more soluble alkaline salts. Carnivora, on the other hand, 

 rrave an excess of phosphate of lime and magnesia, of sulphates 

 and chlorides, more uric acid than the vegetable feeders, but a 

 minimum amount of carbonate and oxalate of lime and silica. 

 The omnivora occupy an intermediate position, the salts of the 

 urine varying with the frequent changes in the food. 



The nature of the food determines the excess of particular 

 salts in the urine and their precipitation in the form of crystals. 



Those carbonates of lime and magnesia which make up the 

 bulk of most urinary calculi in horses and ruminants, are due to 

 the large amount of vegetable acids (citrates, tartrates, malates, 



