370 MATERNAL DYSTOKIA. 



offer a rather serious amount of resistance to the expulsion of the young 

 creature, and demands the services of the obstetrist. 

 The cases recorded are exceedingly few. 



Treatment. 



The indications for treatment, when the hymen is present and an 

 obstacle to birth, are obvious : divide it at once. This division may be 

 made in the middle of the membrane, and does not demand any parti- 

 cular care or surgical knowledge ; though it is well to make a close 

 examination before the incision is made, in order to avoid making a 

 mistake should the membrane appear as a tumour. 



5. Vaginal and Vulvae Constriction or Atresia. 



Stenosis and atresia of the vulva and vagina have not infrequently 

 been recorded as either delaying, or altogether preventing, parturition 

 in animals, according as the obstruction was incomplete or complete. 



This condition may exist previous to impregnation, but to such an 

 extent as to offer no obstacle whatever to that act ; or it may become 

 developed in the interval between impregnation and parturition. Of 

 course, if atresia is complete, and of such a character that the spermatic 

 particles cannot pass into the os uteri, impregnation will not take 

 place, and the animal remains sterile. 



The condition may, therefore, be congenital or acquired. Incomplete 

 congenital stenosis of these passages is not at all uncommon in young 

 animals, in which the vulva and vagina are often so constricted and 

 inelastic, that during copulation they are injured, and this injury tends 

 still more to diminish their calibre and dilatability during pregnancy. 

 Congenital stenosis to a very abnormal degree may sometimes exist, 

 however, without any apparent traumatic influence. 

 I Acquired stenosis or atresia is generally the result of certain diseases 

 or injuries, such as inflammation, suppuration, ulceration, and lacera- 

 tion, often due to difficult parturition. These may lead to hypertrophy 

 and density of the tissues, hard resisting cicatrices, solid adhesions, 

 or partial or complete obliteration. 



Malposition of the vulva may also lead to atresia. I witnessed a 

 case of this kind in an Arab Mare of high pedigree in Syria. The vulva 

 was partly below the ischial arch. 



In primiparae, cases of abortion, in which birth occurs in a hurried 

 manner, as well as when the water-bag is ruptured too soon, or in those 

 breech presentations in which the hind legs are bent forward and only 

 the hocks ofier — in all these the narrowness of the vulva and vagina, 

 from lack of preparation, is often an obstacle to parturition, their 

 tissues being "hard." 



But with patience and warm emollient injections, as well as careftil 

 and gradual manual dilatation, this obstacle may be overcome. When 

 birth is taking place too hurriedly, Eainard recommends closing the 

 animal's nostrils and opening its mouth, pulling out its tongue and 

 pressing on the loins to prevent its arching the back and straining. It 

 is very rare that the resistance is serious, and in the great majority of 

 cases birth occurs spontaneously, or with trifling assistance. 



Some authorities, however, have met with instances in which it was 

 necessary to dilate the vulvar orifice by incision, in order to prevent this 

 part being lacerated, and to spare the animal pain and subsequent 

 deterioration. 



