376 Veterinary Obstetrics 



fetus has come to rest against the diaphragm and has acquired a 

 longitudinal diameter which equals or exceeds that of the 

 abdominal cavity of the mother, the more posteriorly situated 

 end of the fetus, with its membranes, pushes up into the pelvis 

 to the OS uteri. The os uteri may itself be pushed back toward 

 the vulva, and in some cases, when parturition is near, especially 

 in the cow and ewe, the os uteri becomes displaced backward to 

 such a degree that it may even appear between the lips of the 

 vulva when the animal is lying down. This prolapse of the 

 vagina and cervix in pregnant ruminants sometimes requires the 

 attendance of the obstetrist. See Ante-partum Prolapse of the 

 Vagina. 



On the other hand, in some animals with exceedingly pen- 

 dulous abdomens, or in that pathologic condition where rup- 

 ture of the abdominal floor has occurred so that the fetus passes 

 through the muscular floor of the abdomen to rest against the 

 skin, the uterus is dragged abnormally downward and forward 

 so that the vulva and anus are drawn inward and present a con- 

 cavity. 



In multiparous animals the uterus lies folded upon itself very 

 much the same as the intestine. Fleming states that, in the pig, 

 each cornu of the uterus lies above the corresponding line of 

 mammae. This, however, is impossible, since, when there are 

 6 or 7 fetuses in one cornu, their combined length is at least 

 double that from the pubis to the diaphragm. Consequentl)^ 

 the}' cannot be arranged in a straight line, but the cornu must 

 be thrown into folds to accommodate the disposition of the 

 fetuses contained within it. 



The direction of the uterus in our domestic animals is very 

 simple. Its weight and the horizontal position of the body tend 

 constantly to keep it in an antero-posterior direction, in a general 

 line with the long axis of the body, modified only in those cases 

 of multiparous animals, in which the cornua are too long to lie in 

 a direct line, and in the larger herbivora, in which the uterus 

 may be slightly displaced to the right or left by great viscera. 



In those animals like the cow and mare, in which the ab- 

 domen may be very pendulous, there may be a somewhat marked 

 deviation of the uterus downward, which would cause the os 

 uteri to present .somewhat upward, but this is not of such a 



