' Examination of the Cervical Canal 99 



complete assembling of available data for diagnosis and 

 prognosis. During vaginal palpation, the operator logi- 

 cally palpates the os uteri externum for the uterine seal as 

 an indication of pregnancy. When a healthy heifer is preg- 

 nant 30 days or more, if the examiner will press the tip of 

 his index finger, without oil, vaseline, or other lubricant, 

 against the os uteri externum for a short interval, and then 

 carefully withdraw it, he is able to recognize in the os a 

 small, highly adhesive seal. The seal grows and expands, be- 

 coming more and more recognizable throughout pregnancy. 

 Its presence is a warning against the invasion of the cervi- 

 cal canal until ample evidence is at hand that the seal is 

 spurious. 



3. The Examination of the Cervical Canal and 

 Douching the Uterus 



Having applied the uterine forceps either to the lips or to 

 the sides of the cervix, and satisfactorily determined that 

 the animal is not pregnant, the operator may exert traction 

 and draw the vaginal end of the cervix back to the vulva or 

 as near thereto as is safe. Continuing a safe degree of 

 traction and drawing the handles of the two pairs of forceps 

 apart, he brings the vaginal end of the cervix into view. If 

 there is good light from a window behind the cow, the parts 

 may be satisfactorily examined visually or in the absence of 

 efficient natural light, one may secure excellent illumination 

 by using a reflecting electric lamp on an extension cord, or 

 an ordinary flash light. The examiner should note the state 

 of the mucous membrane at the os uteri externum. In the 

 healthy heifer, the vaginal end of the cervix terminates in 

 a sharp cone, at the apex of which opens the very narrow 

 os uteri externum with its mucosa everywhere in contact. 

 The index finger cannot be inserted without violence. Usu- 

 ally it will admit for a short distance, without resorting to 

 force, a smooth sound, one-fourth inch in diameter. The 

 vaginal mucosa envelops completely the entire cone of the 

 vaginal portion of the cervix and invaginates slightly into 

 the os uteri externum. 



