290 



3fA TERNAL D YSTOKIA. 



are various. They may belong to the bones of this region, or to its 

 connective tissue ; and they always more or less diminish one or more 

 of the dimensions of the parturient canal, and offer an obstacle to the 

 passage of the foetus. These cases, however, are somewhat rare ; they 

 are generally found to be due to complete deformity of the pelvis, 

 exostoses, fractures, or tumours. 



Complete Deformity of the Pelvis. 



As has been observed, complete deformity of the pelvis is very rare 

 among animals. "When due to rachitism, it is most frequently noted 

 in the Pig. In this animal the pelvis is sometimes greatly distorted, 

 and not unfrequently there is accompanying deviation in the vertebral 

 spine. This condition is seldom seen in other creatures. 



Saint-Cyr informs us that in the Museum of the Lyons Veterinary 

 School, there is the pelvis of a Mare and another of a Female-Ass, which 



Fig. 81. 

 Completely Defoejied Pelvis : Mare. 



present a very remarkable degree of general constriction, and which 

 must have offered a very serious obstacle to parturition if the animals 

 had ever been pregnant. That of the ]\Iare (Fig. 81) is singularly 

 depressed on both sides, the ischia, and especially the pubis, being 

 atrophied with respect to size. The oval foramina and cotyloid 

 cavities are close together, the floor of the pelvis is extremely con- 

 tracted and angular, and the pubic arch is hypertrophied. In this 

 specimen there is a very notable diminution in the different diameters 

 of the pelvic cavity ; the supero-inferior, instead of being about Qh inches 

 is only about 6, and the bis-iliac diameter is but 4J, instead of being 

 7J to 8 inches. 



The diagnosis of this deformity ought not to be difficult, especially 

 when it is so marked as in this instance. Vaginal exploration should 

 soon discover it, and the diminution in size may be approximately 

 determined by spreading the fingers, and in this way measuring the 



