Inversion of the Uterus 829 



dairy stables, where the accident is far more common than in the 

 field. In our experience, among cows which are kept for rais- 

 ing beef cattle and constantly run at large, the accident is 

 almost never seen. 



Anatomical peculiarities exert some influence upon the proba- 

 bility of inversion of the uterus. We have already related, on 

 page 29, that the broad ligaments of tlie uterus of the cow are 

 attached to the abdominal walls more posteriorly than those of 

 the mare, and hence the uterus is not held so far forward in the 

 peritoneal cavity. When pregnancy occurs, the broad ligaments 

 become greatly amplified, and when parturition occurs these bands 

 are so greatly elongated that the uterus can readily become pro- 

 lapsed, so far as these attachments are concerned, without their 

 becoming ruptured or even veiy greatly stretched. In spaying 

 the non-pregnant cow we can draw the ovary very nearly to the 

 vulva. From this standpoint, the cow is more liable to prolapse 

 than is the mare. On the other hand, the cervix of the uterus 

 in the cow is more narrow and contracts more promptly than 

 that of the mare, so that, if the contraction takes place normally 

 in each, the mare would be more subject to the accident from this 

 standpoint than the cow. 



We must constantly recognize, as a contributory cause of pro- 

 lapse, anything which greatly debilitates the animal. Difficult 

 and prolonged labor is so frequently followed by prolapse of the 

 organ that it must be regarded as one of the causes of the acci- 

 dent, although it by no means follows that dystokia should 

 directly cause this displacement. We repeatedly see cases where 

 powerful traction has been employed without inducing any dis- 

 placement of the uterus. On the other hand, we meet with 

 cases of prolapse of the organ where the parturition has been 

 natural and easy. 



When the fetal membranes are abnormally retained, and cause 

 irritation and expulsive efforts, they are liable to cause a prolapse 

 of the organ. Eversion is further facilitated by the fact that, in 

 the presence of the membranes, the cervix of the uterus does not 

 undergo its normal constriction. Very naturally, any injudi- 

 cious traction upon retained membranes tends to cause prolapse 

 of the organ. For example, when the chorion of the mare is 

 separated from all parts except the apex of the gravid cornu, 

 .severe traction upon the membranes is liable to cause the beginning 



