Rupture of the Perineum 859 



abrupt increase of diameter, which may cause an increased 

 tension to bear upon some portion, especially the superior com- 

 missure of the vulva. We have seen complete rupture of the 

 perineum in the mare, where the foal had been torn away by 

 powerful traction exerted upon the two anterior limbs, while the 

 head and neck of the foal were completely deviated to the side. 

 The prognosis of rupture of the perineum depends chiefly upon 

 the character and degree of the lesion. When the rupture results 

 in a recto- vaginal fistula, the prognosis is favorable for the life 

 of the animal, and moderately favorable as to her usefulness, but 

 as a general rule the animal makes an objectionable noise when 

 being trotted, owing to the involuntary escape of flatus from the 

 rectum through thevulva. It is possible for such animals to breed, 

 providing the fistula is of such a character that the penis of the 

 stallion will not become engaged in the opening during coition. 



The probability of bringing about a recovery in such cases, 

 that is a complete recovery by obliteration of the fistula, is re- 

 mote. We have made repeated efforts to bring about a closure 

 of the fistula in two cases in the mare, and in each instance not 

 only failed absolutely in our object, but left the fistula rather 

 larger than smaller. A few cases of complete recovery from this 

 injury appear to be recorded, but the failures are apparently left 

 unpublished. 



When the rupture involves the complete destruction of the 

 sphincters of the anus and vulva, and includes the floor of the 

 rectum and roof of the vagina for some inches forward, the 

 prognosis is again highly favorable in respect to the life of 

 the animal. As in the preceding condition, there have ap- 

 peared from time to time records of complete recovery follow- 

 ing sutures, but here again there has been ominous silence in 

 reference to the failures. How great the proportion of failures 

 we do not know, but it must certainly be very, very high, 

 probably more than 90%. Personally we have neither obtained a 

 recovery nor had the privilege of observing one in the hands of 

 other veterinarians. 



In almost all cases the wounds granulate and finally cicatrize, 

 but the lips of the wound do not unite, and the anal and vulvar 

 cavities remain one, with the feces dropping into the vulva. An 

 animal with complete perineal rupture which has failed to unite, 

 is usually sterile. The conditions are such that successful 



