170 DISEASES OF THE URINARV AND SEXUAL APPARATUS 



length), Fig. 69. The subject is laid on the left side or back and held in 

 that position by an assistant. The prepuce is pushed back behind the 

 swelling of the gians and held firmly with the left hand (see Fig. 70). 

 Now grasp the catheter with the right, of course, first seeing that it 

 has been well lubricated with some oil or cosmoline and that it contains 

 the wire-stylet, and introduce it into the urethra; if it is pushed forward 

 up the canal and meets with an obstruction at the posterior end of the 

 bone of the penis, it is due to a flexure of the canal and also to the fact 

 that the diameter of the urethra is less and the part at that portion 

 has slight contractile properties. By a gradual pressure the stricture is 

 overcome and the catheter passed upward to the arch of the perineum; 

 here the wire-stylet must he withdrawn from the catheter at least one- 

 third, so as to allow the catheter to round the curve of the ischial arch; a 



" Fig. 70. — Passing the catheter. 



gradual pressure soon brings it into the bladder, when the wire can be 

 removed entirely. 



In the bitch catheterization is very difficult at times, for while the 

 instrument should be introduced along the middle line of the vestibule, 

 freciuently it is almost impossible to find the narrow opening of the 

 urethra, and a vaginal speculum is sometimes necessary to locate the 

 position of the opening; we generally use a metallic catheter, either 

 silver or German silver (Fig. 71). The instrument is passed up on the 

 floor of the vagina until it comes in contact with the urethral opening 

 (see Fig. 72) ; this is closed with a slight sphincter (the so-called "urethral 

 valve); this is soon overcome and the catheter passed into the bladder 

 without difficulty, except in cases where the urethral opening is extremely 

 small. 



