Examination of the Cervical Canal 103 



by means of dilator, catheter, or sound. The dilator (Fig. 

 39) is usually preferable. As will be seen in Figs. 40, 41, 

 the cervical canal is extremely narrow, sinuous, and at times 

 angular, and the free margins of its annular mucous folds, 

 directed toward the vagina, offer serious obstacles to the 

 prompt passage of an instrument into the uterus. The 

 canal usually extends sharply downward and forward, very 

 slightly to the right, for one to one and one-half inch ; then 

 bends sharply upward and forward, and thence approxi- 

 mately forward, with slight divergences, to the cavity of the 

 uterus. The windings of the canal are difficult to follow and 

 the free margins of the annular folds, directed toward the 

 vagina, constitute deep culs-de-sac, into which the dilator 

 tends to pass and its progress to be thus arrested. The 

 operator is, therefore, to take these conditions into account 

 and, without violence or force, retreat and advance at vari- 

 ous angles, in his effort to follow the tortuous canal and 

 evade the barriers formed by the mucous folds. Sometimes 

 the free edges of the mucous folds appear to become pushed 

 forward by the instrument into the lumen of the canal and 

 occlude it, preventing for the time the passage of the instru- 

 ment. In disease, the annular folds often become so hyper- 

 trophied and their bases so sclerotic as to cause acute bend- 

 ings of the canal and to close quite firmly its lumen, making 

 it exceedingly difficult and rarely impossible at a given time 

 to pass an instrument through the canal into the uterus. 



The operator needs to be patient here, as well as skilful. 

 Any undue force may rupture the cervical wall and pene- 

 trate the surrounding connective tissue, causing pelvic ab- 

 scessation, as shown in Fig. 42, with extreme peril to the 

 physical and breeding life of the animal. If the operation 

 cannot be made to succeed at first effort, it should be sus- 

 pended for the time and undertaken later. I have worked 

 for an hour or two at a time, four or five times in succession, 

 before finally succeeding in reaching the uterine cavity. 

 However, it is always infinitely better to try repeatedly, and 

 finally fail, than to use force and ruin the animal, not so 

 much because of the breeding value of such an animal, since 



