The Uteri?ie Seal 



119 



Sometimes a false uterine seal forms, as a result of dis- 

 ease, as in retained corpus luteum and in cervicitis. The 

 uterine seal persists when the fetus dies and desiccates, and 

 when the embryo dies and the embryonic sac remains to con- 

 stitute a "mole". 



The uterine seal may fail to form or it may break down 

 when the cervix is badly diseased and abortion is imminent. 

 Consequently the presence of the typical seal not only gives 

 reliable evidence of pregnancy, but adds to that a certain 

 feeling of security, suggesting not only that the animal is 



Fig. 45a— The Uterine Seal in Longitudinal Section. Cow. 

 /, Os uteri externum ; 2, os uteri internum ; 3, base of second annular cervi- 

 cal fold ; 4, uterine seal extending throughout the length of the canal. 



pregnant, but perhaps safely so. In severe purulent vagini- 

 tis or purulent cervicitis of the vaginal portion, the uterine 

 seal may exist in the uterine end of the cervical canal and be 

 displaced by pus in the vaginal portion. The seal may then 

 be recognized by palpating it with a metallic sound, uterine 

 catheter, or dilator introduced cautiously along the cervical 

 canal. While the uterine seal is one of the most important 

 evidences of pregnancy, it has its limitations in diagnosis 

 and, like most signs, needs to be considered in conjunction 

 with other findings. 



