310 BOVINE OBSTETRICS 



the lateral wall of the gravid and prolapsed Lorn, leading into 

 the empty cornu. 



Prolapsus uteri is frequently seen in the cow, especially 

 in lymphatic, excessively-fed and old animals, which have 

 calved repeatedly; it is comparatively rare in properly fed 

 young animals. 



It follows difficult and normal labor, also the partus prema- 

 turus, and may occur any time after the calf is born until the 

 cervix uteri closes. As long as the cervix uteri is sufficiently 

 dilated to allow the hand to pass, inversion and prolapsus are 

 still possible. 



Causes. — They may be divided into two main groups : 

 predisposing and direct causes. 



PREDISPOSING CAUSES. 



(a) Relaxation of the mesometrium. One must not think 

 that the broad ligaments are stretched to such an extent that 

 they participate in the whole displacement of the inverted horn. 

 In a complete prolapsus only one half of their normal length 

 is involved, as they are closely attached to the body of the 

 uterus and do not carry but a small portion of the pregnant 

 horn. Therefore one half of the length of the inverted horn 

 may project at the* vulva before the broad ligaments are 

 stretched at all. 



(h) Sloping position. This induces a displacement of the 

 uterus toward the posterior portion of the abdominal cavity. 

 It also causes violent after-pains, in which the abdominal mus- 

 cles are actively concerned, thus rendering it possible that 

 the floor of the impregnated horn becomes inverted by the 

 pressure of the abdominal viscera. Into the space thus created 

 more intestines crowd, increasing inversion and prolapsus. 



(c) Insufficient uterine contractions. As a result of this the 

 cervix uteri remains open after parturition, permitting easy 

 passage of the inverted horn. The surface of the dilated horn 

 is besides much greater, so that the probability of an inwr- ion 

 under such circumstances is greater than in a contracted state 

 of the uterus. 



