LITHOTRITY. 1 23 



of operation, which has already been shaved and rendered 

 thoroughly aseptic. The urine having been previously drawn 

 away, and the catheter left in position in order to clearly 

 define the outline of the urethra, an incision is made directly 

 on to this in the perineal region, about midway between the 

 testes and the anus. An aperture of sufficient size to introduce 

 the lithotrite is made in the urethra, and the catheter steadily 

 withdrawn. The curved end of the lithotrite is introduced, 

 passed round the pelvic border, and into the bladder. Search 

 is made for the calculus, which must be manipulated until it 

 is firmly fixed between the jaws of the instrument, when steady 

 pressure is exerted upon it, in order to break it up into small 

 pieces, care being taken not to include the mucous membrane 

 of the bladder. Some of the larger pieces may require a second 



Fig. 66a. 

 Urethral Dilator (Sewell's). 



application. The fragments are then got rid of, either by 

 forceps or by continual irrigation with an antiseptic fluid, 

 such as solution of chinosol. The wound is then sutured, the 

 urethra itself with fine silk, and the muscles and skin separately, 

 the whole being covered with iodoform or orthoform and collo- 

 dion. In small patients it is sometimes impossible to suture the 

 urethra, and even in the larger ones some operators prefer to 

 merely suture the skin and muscles. Where the animal is of a 

 quiet disposition a catheter may be left in the urethra for two 

 or three days with advantage, but if it gives rise to irritation 

 and consequent continual efforts to lick the parts its continued 

 use is best avoided. 



After-treatment must depend a little upon the progress made ; 

 diet should be of an easily digestible character and sparing in 



