CONCBETIONS AND FOEEIGN BODIES 135 



Describe the wrinary calculi of the various animals. 



Horse : There are two kinds, those of the bladder and 

 those in the urethra. Their composition is about the same, 

 consisting of traces of iron, oxalate of lime and a greater 

 amount of carbonate of lime. The vesical calculi are of nut 

 to fist size, are hard, either egg or disc shaped, with a smooth 

 or mulberry-like surface and of yellowish color. One or 

 several stones, as well as a finer sediment ("gravel"), may be 

 found. The urethral calculi are usually found at the ischial 

 curvature and are of pigeon egg to chestnut size. 



Cattle : These are composed of carbonate and oxalate of 

 lime. As a rule, a number of round or disc-shaped pea-sized 

 stones, glistening and yellowish, are found at the curve of the 

 urethra. 



Dog ; These are usually small, of pea size and present in. 

 numbers. The surface may be rough or by continuous rub- 

 bing may have become smooth. They are composed of 

 oxalates, urates and triple phosphate, filling the whole urethra, 

 being wedged at the incurvated portion of the penial bone. 



Describe intestinal calculi. 



These are also known as enteroliths in the horse and are 

 of little surgical interest unless they can be reached from th& 

 rectum. They are found in the caecum and colon, causing 

 obstruction and colics. They are primarily composed of triple 

 phosphate, formed by the precipitation of the phosphate of 

 magnesia (coming from the food ; bran, for instance) by the 

 ammonia found in any barn. The ammoniaco-magnesium 

 phosphate and calcium phosphate— that is, the triple phos- 

 phate— crystalizes around a kernel of oats or any other foreign: 

 body, and the foundation to a calculus is laid. 



In cattle the so-called hair balls are quite often found in 

 the rumen. These are also called bezoars and are made up of 



