378 FCETAL DYSTOKIA. 



and especially if the muzzle of either or both of the parents is short 

 and the cranium brachycephalic — as in the King Charles Spaniels, 

 Pugs, and Bull-dogs — parturition is oftentimes extremely difficult, as 

 the forehead in these breeds is very large and cylindrical. This diffi- 

 culty, as has been mentioned, is increased as the number of Puppies is 

 small, as then the latter are more developed. 



With the Coio, the head of the Calf may also be the chief impediment, 

 and provided the young creature is otherwise in .a favourable position, 

 the muffle may pass through the inlet, but the remainder of the head 

 remains fixed like a wedge in the long and almost undilatable bony 

 canal. The head is often so firmly wedged at this part that it can 

 scarcely, even with much force, be advanced or pushed forward, and 

 this "wedging" is always one of the most serious difficulties which 

 the obstetrist has to overcome. 



With the Mare, the head of the Foal is smaller, longer, and more 

 tapering than that of the Calf, and meets with much less resistance in 

 passing through the comparatively short and wide canal. But as 

 Saint-Cyr points out, and as w^e have previously shown, in the Equine 

 and Bovine species the young creature finds more difficulty when the 

 anterior part of its body — chest and shoulders — begins to enter this 

 part ; and from their respective dimensions it is evident that, even 

 under ordinary conditions, the anterior region of the foetal trunk must 

 submit to a certain degree of diminution in order to pass the pelvic 

 inlet of the mother. 



The limits within which this diminution is compatible with physio- 

 logical parturition are not yet perfectly ascertained ; though there can 

 be no doubt whatever — for we have facts to prove it — that the develop- 

 ment of the young creature may be so exaggerated that sufficient 

 reduction cannot be effected to allow of its being born. 



In some cases the head is so large that it can scarcely pass through 

 the pelvis of the mother ; but it is generally the thorax that forms the 

 greatest obstacle — especially in the Cow, and if it is to get through 

 the genital canal this is the part that has to undergo most reduction by 

 compression. In other instances, and especially with the Foal, the 

 passage of the croup presents the greatest obstacle, and the difficulty 

 may even be serious. 



Prognosis. 



In such cases as those we are now studying, in which birth is 

 delayed through undue development of the foetus, it generally happens 

 that the membranes have ruptured and the liquor amnii has escaped 

 at an early stage ; consequently, the maternal passage is dry and 

 tenacious, and perhaps swollen and irritated ; while the foetus, no 

 longer protected in its hydrostatic bed, is directly exposed to the 

 uterine contractions, and in proportion as these are energetic, so does 

 it the more rapidly succumb. The mother, in turn, becomes exhausted 

 through unavailing efforts at expulsion, and if judicious assistance is 

 not opportunely rendered, is not long before it also perishes. 



It will, therefore, be seen that a prognosis in such cases of dystokia 

 cannot always be of a favourable kind, as very often the death of the 

 foetus, if not of the mother, has to be taken into consideration. More 

 particularly is this the case with the smaller animals— and especially 

 the Bitch, though, as has been shown, the larger females, if they do 

 not die so frequently, yet are not exempt from danger. 



