DIFFICULT PAKTUEITION. 171 



FIBROUS CONSTRICTION OF VAGINA OR VULVA. 



This is probably always the result of direct mechanical injury and 

 the formation of rigid cicatrices which fail to dilate with the re- 

 mainder of the passages at the approach of parturition.' The pre- 

 sentation of the fetus in the natural way and the occurrence of suc- 

 cessive and active labor pains without any favorable result will direct 

 attention to the rigid and unyielding cicatrices which may be incised 

 at one, two, or more points to a depth of half an inch or more, after 

 which the natural expulsive efforts will usually prove effective. The 

 resulting wounds may be washed frequently with a solution of 1 part 

 of carbolic acid to 50 parts of water, or of 1 part of mercuric chloride 

 to 1,000 parts of water. 



FETUS ADHERENT TO THE WALLS OF THE WOMB. 



In inflammation of the mucous membrane lining the cavity of the 

 womb and implicating the fetal membranes, the resulting embryonic 

 tissue sometimes establishes a medium of direct continuity between 

 the womb and fetal membranes ; the blood vessels of the one commu- 

 nicate freely with those of the other and the fibers of the one are 

 prolonged into the other. This causes retention of the membranes 

 after birth, and a special risk of bleeding from the womb, and of 

 septic poisoning. In exceptional cases the adhesion is more extensive 

 and binds a portion of the body of the foal firmly to the womb. In 

 such cases it has repeatedly been found impossible to extract the 

 foal until such adhesions were broken down. If they can be reached 

 with the hand and recognized, they may be torn through with the 

 fingers or with a blunt hook, after which delivery may be attempted 

 with hope of success. 



EXCESSIVE SIZE OF THE FETUS. 



It would seem that a small mare may usually be safely bred to a 

 large stallion, yet this is not always the case, and when the small size 

 is an individual rather than a racial characteristic or the result of 

 being very young, the rule can not be expected' to hold. There is 

 always great danger in breeding the young, small, and undeveloped 

 female, and the dwarfed representative of a larger breed, as the off- 

 spring tend to partake of the large race characteristics and to show 

 them even prior to birth. When impregnation has occurred in the 

 very young or in the dwarfed female, there are two alternatives — to 

 induce abortion or to wait until there are attempts at parturition and 

 to extract by embryotomy if impracticable otherwise. 



CONSTRICTION OF A MEMBER BY THE NAVEL STRING. 



In man and animals alike the winding of the umbilical cord around 

 a member of the fetus sometimes leads to the amputation of the 

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