238 Surgical Diseases and Surgery of the Dog 



the bifurcation of the latter. They are embedded in more or less 

 connective tissue and fat and must be carefully sought for when 

 any extended operation is undertaken. The ureter crosses the vas 

 deferens on either side, and the latter must not be mistaken for the 

 former, an error which has befallen some experimenters. 



PASSAGE OP THE CATHETER AND SOUND. 



Catheters made of cotton web or soft rubber, preferably the 

 former material, are best adapted for use on the male. Their length 

 should be from fifteen to eighteen inches, and sizes three to twelve 



No. 48. Female Catheter. 



'(metric scale) meet all requirements. A wire stylet facilitates pas- 

 sage of the instrument, but it must be used with extreme caution 

 as it is very easily thrust through the wall of the instrument. 



Bougies for treatment of stricture are used in somewhat larger 

 sizes. For the female the catheter should be of the same material 

 as for the male, or, better still, of metal in the same sizes. 



These instruments should always be rendered sterile and be 

 well lubricated before being used. 



PASSAGE OF THE CATHETER IN THE MALE. 



Secure the animal in the dorsal position and stand facing its 

 left side. Expose the penis by retracting the prepuce with the left 

 hand. Holding the catheter in the right hand insert it within the 

 urethral orifice and pass it gently along the canal. Some slight 

 impediment is generally met with at the level of the posterior ex- 

 tremity of the penial bone owing to a decrease in the caliber of the 

 urethra at that point, but it is easily overcome by a little increased 

 pressure. An obstruction at this point indicates a pathologic con- 

 dition. As soon as the ischial arch is reached, the wire stylet is 



