PVsroKIA FROM rELVlC UOA.STRJrTJoX. 28» 



BOOK I. 



MATERNAL DYSTOKIA. 



TnK pathology of parturition, as has been mentioned, includes disturb- 

 ances produced by excessive or tumultuous pains and too feeble pains, 

 and derangement caused by too great an obstacle to birth. We have 

 sufticiently described the first ; and we have now to deal with the 

 second, in so far as the mother is concerned. The maternal obstacles 

 to parturition are related to the too great resistance offered by the 

 parturient passages, either in their hard or soft parts. These obstacles 

 have been grouped in the preceding table under the heading of j^clvic con- 

 strictio)i, displacement or change in relations of the uterus, and morbid 

 alterations of tlie maternal organs. 



CHAPTER I. 



Dystokia from Pelvic Constriction. 



DvbTOKiA from constriction of the pelvis is sometimes observed in 

 animals ;' though less frequently, perhaps, than in woman, in whom 

 constitutional causes and the different position (vertical) of tliis region, 

 operate largely in producing diminished dimensions of its cavity. Any 

 alteration in the dimensions or shape of the pelvis, whether general or 

 partial, is a more or less serious cause of dystokia, and in some cases 

 may render delivery absolutely impossible. A pelvis generally reduced 

 in all its dimensions is sometimes noticed in the lai'ge, as well as tlie 

 small domesticated animals. 



On the Continent of Europe, this has been observed miOre particularly 

 among some of the small common breeds of Cattle — such as tlie 

 liretonnc, and certain of the grey Swiss breeds, as the Fribourgeoise. 

 These have the ischia pointed and the tail attached high above them. 

 Leconte has observed this conformation in animals the produce of a 

 cross between large Norman Mares and pure-bred Horses, which 

 have a sharp croup. There is often a relative narrowness of tlie pelvis 

 in animals of small size that have been put to larger males. This has 

 been witnessed in the Mare and Bitch ; and as the young are propor- 

 tionately larger than the pelvis can accommodate in parturition, we 

 have here a cause of dystokia. 



An abnormal inclination of the pelvis has been supposed by some 

 writers to exercise an unfavourable inlluence on parturition, but this 

 has been denied by others. Provided the other conditions of normal 

 parturition are present, no ditViculty should be experienced in delivery ; 

 but if, added to this state, there is a narrow pelvis, then obstetrical 

 operations would certainly be rendered more serious. 



Deformities which occasion irregular constriction of the pelvic cavity 



' A naturally wide polvis — <>r r.ither an excea« in width--observfd more particularly 

 in aninialK of a Ijinphatic temperament, and especially in Cows, al'-ni; with an extra- 

 ordinary -supplenesis and laxity of the soft parts in thi.s region, h.'us the inconvenience «>f 

 renderini; i)4irturition tmi ea-^y, it would .ipjiear. For this facility is supposed, and not 

 without re;i'<on, to bring about such complic.iti<ms as inversion of the vagina and uterus, 

 placenta) retention, and even predispose*, according to some authorities, to Titulary 

 apoplexy in the Cow, and metritis in the other animals. 



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