STONE IN THE BLADDEE. 445 



tbe cut has to be made. A special kind of forceps is introduced 

 through the opening into the bladder to catch hold of and remove 

 the stone. A capable assistant should pass his hand in1;o the 

 rectum and aid the operator by directing the stone towards the 

 claws of the forceps. The precautions to be adopted while per- 

 forming this operation, are described in " Veterinary Surgery," 

 by Peuch and Toussaint, from which I compiled the foregoing. 

 English veterinary surgeons, instead of filling the urethra with 

 water, usually pass a catheter, and make the opening by cutting 



Fig. 145. — Urinary calculus. 



down upon it. They also, as a rule, perform the operation with 

 the horse placed on his back on the ground. Wlien the deposit 

 is in the form of a soft mass, it will have to be removed by a 

 specially made spoon. 



In the mare, the stone can be removed, without the use of the 

 knife, through the urethra, which is larger than that of the horse, 

 and wliich opens on the floor of the vagina, at about 4 inches from 

 the outside. The opening of the female urethra into the vagina 

 is guarded by a valve, which points to the rear and can be easily 

 lifted up with the finger. 



