URETHRAL CALCULI. 467 



the catheter; the incision may be enlarged, and the 

 catheter withdrawn, when the forceps, nicely oiled, should 

 be inserted and carefully passed along the canal, the other 

 hand being placed in the rectum for the purpose of guiding 

 the calculus into the forceps. The operation is one rather 

 difficult to perform, requiring on the part of the surgeon 

 great care and patience, as well as a good knowledge of the 

 anatomy of the parts. The principal danger is from in- 

 filtration of urine into the tissues setting up irritation, ery- 

 sipelas, and perhaps causing death. Calculi may be removed 

 with greater ease from females, especially amongst cattle. 



URETHRAL CALCULI. 



Urethral calculi differ from those previously mentioned 

 only in situation. Calculi existing in the kidneys are 

 known as 'renal calculi,' and on reaching the bladder 

 become known ns ' cystic ' or ' vesical calculi,' the same cal- 

 culi on reaching the urethra being termed ' urethral calculi,' 

 the general term 'urinary calculi ' being employed to desig- 

 nate calculi in connection with any portion of the urinary 

 system. In cattle troubled with urinary calculi, calcareous 

 deposits may usually be found on the hair around the pre- 

 puce, and these deposits can be detected in the urine of both 

 horses and cattle affected in this manner. Sometimes the 

 calculus is found to be encysted in the bladder, but although 

 encysted may be moveable. The presence of calculi may 

 set up irritation in the mucous membrane of the urethra of 

 the ox, and stricture result, stricture being in nearly every 

 case caused by calcareous deposits. In such a case the 

 catheter cannot be passed, the only remedy being to cut 

 into the urethra and divide the stricture ; this operation in 

 fat cattle will be found rather difficult, but may be easily 

 performed on a lean animal. The animal should be allowed 



30—2 



