124 Diseases of the Genital Organs 



sometimes to await a quite definite increase in volume before 

 this becomes of distinct value in determining pregnancy. 

 The same may be true of heifers which have been sterile for 

 a long period and in which the uterus has undergone en- 

 largement because of chronic endometritis. 



As a general rule, however, heifers which have conceived 

 at all promptly show distinct and characteristic enlargement 

 of the uterus within twenty to thirty days after conception, 

 and cows at any time from thirty to sixty oi- seventy days. 

 The enlargement of the uterus as a result of conception is 

 very characteristic. The organ may be enlarged from a 

 great variety of causes, but the enlargement due to other in- 

 fluences than pregnancy differs materially and clearly in al- 

 most every case. In pregnancy the uterus is smooth and even 

 in outline, firm, tense, and fluctuating. Except in case of 

 twin pregnancy, the pregnant horn is much larger than the 

 other and regularly corresponds with the corpus luteum of 

 pregnancy. While the corpus luteum is regularly palpable 

 in early pregnancy in the cow, it is not so in the mare be- 

 cause it is hidden deeply in the hilus of her ovary. At the 

 region of the internal os uteri, the superior uterine wall of 

 the pregnant cow rises up suddenly like a terrace instead of 

 sloping forward gradually as is observed when pus or lymph 

 distends the organ. The firmness of the uterine wall is in 

 marked contrast also to its character when the organ is dis- 

 tended with pus or lymph. In pregnancy the uterus is dis- 

 tinctly firm and exhibits to the touch a sense of vigor and 

 life. When lymph distends the uterus, the walls may be thin 

 as in pregnancy but they are almost always soft and flaccid 

 and the horns are usually somewhat equally filled. In rare 

 instances, owing to compression of the cervical canal due to 

 sclerotic swellings in the cervical walls associated with cer- 

 vicitis, menstrual debris is retained, distending the uterus 

 quite firmly and giving a tension much like that of preg- 

 nancy, but the two horns are alike and there is but one cor- 

 pus luteum. Usually in such cases no uterine seal is pres- 

 ent. When the organ is distended with pus, the contents do 

 not move as freely as the fetal liquids. The uterine walls 



