566 Diseases of the Genital Organs 



tion inverts into the cervical portion and finally prolapses, 

 and the afterbirth comes away with the amniotic surface of 

 the chorion external. 



The duration of the retention of the fetal membranes is 

 further modified by the virulence of the infection. The mild- 

 est recognizable type may have only a brief duration be- 

 cause the involved tissues retain or recover in part their 

 physiologic functions and act effectively before firm incar- 

 ceration occurs. At the other extreme, even when a calf is 

 born, the infection may be so virulent as to cause necrosis of 

 all the cotyledons with sloughing through their necks within 

 two or three days after calving, thus ending the retention. 



The symptoms of retained fetal membranes are those of 

 the underlying metritis with the addition of the recognized 

 presence of the membranes. The retention of the membranes 

 is usually evident because some portions protrude from the 

 vulva. The part most commonly protruding is the umbilic 

 cord, but it may be a portion of the amnion, or the chorion 

 from the non-gravid horn. 



Retained fetal membranes are not always visible. If the 

 uterus is very paretic so that involution is very imperfect 

 and the uterus retains approximately its gravid size, the 

 retention of the membranes at the ovarian end retracts the 

 stump of the umbilic cord into the vagina or even into the 

 uterine cavity. The retention then becomes recognizable 

 only upon clinical examination. This constitutes one of the 

 most dangerous types of retention because the layman fails 

 to recognize it, and the veterinarian, unless on his guard, 

 may err in diagnosis. It finally leads to another interest- 

 ing phase of retention of the fetal membranes. When the 

 placentitis has finally run its course to that point where the 

 membranes are no longer attached' to the uterus. Whether 

 detachment has occurred through suppuration within the 

 crypts or necrosis of the cotyledons, the cervix, which has 

 not participated extensively in the disease processes, may 

 have so contracted that the enfeebled uterus is unable to 

 force out the loose-lying membranes, with perhaps the ne- 

 crotic cotyledons still attached to the membranes and de- 



