COURSE OF NORMAL BIRTH 73 



The water-bag, so important in the dilation of the genital 

 passage, must not be ruptured until the genital passage is fully 

 dilated, so that all folds of the neck of the womb have dis- 

 appeared. It usually ruptures when meeting with resistance 

 in the genital passage or when protruding at the vulva. A part 

 of the foetal liquor then escapes. Shortly after it is followed 

 by the amniotic bladder. The time between the two may be 

 short — ten to fifteen minutes — but may amount to several hours. 

 During the pains, quite intense at this stage, the cow rests. 

 most comfortably upon the right side. I have often observed 

 that it is very uncomfortable for the cow to lie upon the left 

 side and that she rises immediately. The position of the rumen 

 explains sufficiently why lying upon the left side when con- 

 tinued for some time creates tympanites and dyspnoea. In 

 cases of very large foetus, or twins causing great distention of 

 the belly, parturition always should take place on the right 

 side. 



Even during normal parturition the act is retarded, when 

 the amniotic bladder, advanced by the head lying in the shape 

 of a wedge upon the fore legs and passing through the genital 

 canal, appears between the lips of the vulva. It is due to the 

 resistance offered in the vestibule to the dimension of the head, 

 both its bitemporal and vertical diameter. The passage is 

 here very paiuful. While overcoming this obstacle the animal 

 issues an expiratory moaning, or may even bellow. When the 

 head is visible between the labise and past the vestibule, both 

 fore legs arrive beyond the vulva up to the carpi. Now the 

 amniotic bladder bursts, the fluid escapes, and, unless the calf 

 is very large, a few expulsive pains suffice to expel it com- 

 pletely. It gradually has become a habit to open the amniotic 

 bladder in order to extract the calf. The amniotic bladder 

 must be opened when the legs up to the carpi and the head as 

 far as the eyes are visible beyond the labise, in order to prevent 

 complications following an eventual inspiration of the calf. As 

 soon as parturition has advanced to this effect, the placental 

 circulation ceases, be it because the umbilical cord has torn by 

 having been pinched at the pelvic floor, or because pressure 



