DISEASES OF THE HORSE. 167 



Fractures at anj- point of the lateral wall or floor of the pelvis are 

 repaired svith the formation of an extensive bony deposit bulging 

 into the passage of the pelvis. The displacement of the ends of'' the 

 broken bone is another cause of constriction and between the two con- 

 ditions the passage of the fetus may be rendered impossible w^ithout 

 embryotomy. Fracture of the sacrum (the continuation of the back- 

 bone forming the croup) leads to the depression of the posterior part 

 of that bone in the roof of the pelvis and the narrowing of the pas- 

 sage from above downward by a bony ridge presenting its sharp edge 

 forward. 



In all cases in which there has been injury to the bones of the pelvis 

 the obvious precaution is to withhold the mare from breeding and to 

 use her for work only. 



If a mare with a pelvis thus narrowed has got in foal inadvertently, 

 abortion may be induced in the early months of gestation by slowly 

 introducing the oiled finger through the neck of the womb and follow- 

 ing this by the other fingers until the whole hand has been introduced. 

 Then the water bags may be broken, and with the escape of the liquid 

 the womb will contract on the solid fetus and labor pains will ensue. 

 The fetus being small will pass easily. 



TLTIORS IN THE VAGINA AND PELVIS. 



Tumors of various kinds may form in the vagina or elsewhere 

 within the pelvis, and v.hen large enough will obstruct or prevent the 

 passage of the fetus. Gray mares, which are so subject to black pig- 

 ment tumors {melanosis) on the tail, anus, and vulva, are the most 

 likely to suffer from this. Still more rarely the wall of the vagina 

 becomes relaxed, and being pressed by a mass of intestines will pro- 

 trude through the lips of the vulva as a hernial sac, containing a part 

 of the bowels. Where a tumor is small it may only retard and not 

 absolutely prevent parturition. A hernial protrusion of the wall of 

 the vagina may be pressed back and emptied, so that the body of the 

 fetus engaging in the passage may find no further obstacle. When 

 a tumor is too large to allow delivery the only resort is to remove it, 

 but before proceeding it must be clearly made out that the obstruc- 

 tion is a mass of diseased tissue, and not a sac containing intestines. 

 If the tumor hangs by a neck it can usually be most safely removed 

 by the ecraseur, the chain being passed around the pedicel and gradu- 

 ally tightened until that is torn through. 



HERNIA OF THE WOMB. 



The rupture of the musculo-fibrous floor of the belly and the escape 

 of the gravid womb into a sac formed by the peritoneum and skin 

 hanging toward the ground, is described by all veterinary obstetri- 

 cians, yet it is very rarely seen in the mare". The form of the fetus 



