828 l^eterinary Obstetrics 



Once the accident has occurred, its recurrence is probable at 

 the next parturition, and when such animals are rebred thej' 

 should be watched the next time they give birth to young. 



Causes. Prolapse of the uterus has been attributed to a 

 variety of causes. The accident necessarily demands the 

 presence of a freely dilated os uteri, and con.sequentlj' occurs 

 very soon after parturition. It frequently appears immediately 

 after the expulsion of the fetus, in both the cow and the mare. 

 In some instances in the mare, the organ has followed the fetus, 

 and has required immediate replacement. In these instances it 

 seems that the closely investing uterine walls adhere more or 

 less to the fetal body, and tend to be dragged out with it, so that, 

 as the last portion of the fetus escapes from the vulva, the uterus, 

 apparently adherent to it, follows immediately. In other cases 

 in our experience, the foundation for the later prolapse is 

 apparently laid at the time of the act of birth, by the apex 

 of the gravid cornua becoming inverted. We suspect that many 

 of the cases of inversion of the uterus have their foundation in 

 such accident at the time of the expulsion of the fetus, and 

 that, if the uterus were carefully examined at the time, the 

 beginning of what is later to constitute a prolapse would be found, 

 though the prolapse itself may not be complete until after one 

 or more days. Exhaustion of the contractile powers of the uter- 

 us, and the expulsion of the fetus wholly through contraction 

 of the abdominal walls, or with traction, tend to produce the 

 prolapse. 



Aside from a derangement in the contractile power of the or- 

 gan, by which a partial intussusception occurs in the gravid 

 cornu, a very prominent cause is tardy involution of the uterus, 

 with failure of the cervix to contract, consequently leaving the 

 organ more or less open and flaccid. 



A further cause of prolapse of the uterus is the presence of an 

 irritant in the body of the organ, such as infection or retained 

 placenta, each of which may cause expulsive efforts, and at the 

 .same time may delay a proper involution of the organ. 



Closely allied to tardy involution is the question of the com- 

 parative amplitude of the genital passages in the so-called roomy 

 animal, and especially one of a more or less phlegmatic tempera- 

 ment. In this relation we find general influences at work, such 

 as close confinement with overfeeding, which is so often .seen in 



