92 ANIMAL CASTKATlOiN 



the walls veiy tense — a condition which greatly facili- 

 tates the performance of the operation, Tn some mares 

 this tensity of the vaginal walls does not continue for 

 a very long time and while the injection of additional 

 quantities of warm water may cause ballooning to 

 recur, this procedure is unnecessary, as the operator 

 can, by placing the end of a blunt embryotomy hook 

 against the inferior vagino-urethral juncture, just be- 

 low the external os, and gently pushing forward, tense 

 the wall sufficiently to incise the vaginal wall with 

 safety. 



Making the incision through the vaginal wall is the 

 most dangerous part of this operation, as it is easily 

 possible to wound the aorta or one of the iliac arteries, 

 if the utmost care and thought are not exercised in 

 this move. As a matter of precaution these vessels 

 should be located by palpation, this is readily accom- 

 plished as their pulsations are easily recognized. 



Because of the changed relationship of the struc- 

 tures when the vaginal wall is ballooned, the knife is 

 simply thrust forward, but if the wall is tensed by 

 artificial means, the incision is made in an upward and 

 forward direction, and under these conditions there is 

 nTore likelihood of the large vessels becoming injured 

 should the animal struggle when the incision is made. 



The lubi'icated hand conveying an ordinary hooked 

 castrating blade or other suitable knife, is introduced 

 and an opening made in the wall very near the median 

 line of the superior vaginal wall in the immediate 

 region of the fornix ; this incision should at first be 

 long enough to permit the penetration of the finger, 

 and may be enlarged by simply forcing the other fingers 

 gradually, and finally the hand, through the vaginal 

 wall into the peritoneal cavity. Caution should be 



