PROLAPSUS OF THE UTERUS 311 



Violent straining or a sloping position behind, together 

 with insufficient contraction of the uterus, are especially favor- 

 able to inversion (Franck). Strong contraction of the uterus 

 does not encourage inversion, but prevents it, on account of the 

 closure of the cervix uteri. The malposition depends on the 

 straining and displacement of the abdominal viscera toward 

 the pelvic cavity, leading to inversion of the uterus. 



(d) Relaxation of the broad pelvic ligaments. In cows 

 which have calved repeatedly the broad pelvic ligaments are 

 often relaxed. In such animals, when lying low behind, pro- 

 lapsus vagina occasionally is observed. In consequence of 

 this the uterus may be drawn into the pelvic cavity after partu- 

 rition becomes inverted, terminating in an inversion, when 

 straining is severe. 



DIRECT CAUSES. 



(a) Aspiration during parturition (Franck). "When severe 

 tractionis exerted upon a large foetus, so that it is delivered with 

 efforts inch by inch, it may happen that after the hind parts of 

 the calf have passed the pelvic outlet, the cotyledons of the 

 gravid horn present themselves already in the vulva. Active 

 straining is then sufficient to expel the inverted uterus. 

 Irrespective of aspiration, the prolapsus may in such a case be 

 due to the pulling on the after-birth when a good deal of it is 

 wedged in between the calf and pelvic wall. Aspiration may 

 take place (as Franck correctly states) when the entire or nearly 

 all of the foetal waters were discharged previous to traction. 

 As a consequence, the uterus clasps the calf firmly and during 

 its passage inversion, and later prolapsus, is apt to follow. 



(b) The weight of the secundines. This is certainly the most 

 direct cause. After parturition the secundines are still con- 

 nected with numerous cotyledons, only a portion hanging from 

 the vulva. The more foetal placentae become detached, the 

 larger the piece hanging from the vulva and the greater the 

 traction exerted upon the cotyledons which are still united. 

 When the adhering placentae lie in that portion of the horn 

 turned toward the abdominal cavity, it may be readily inverted 



