448 



FCETAL DYSTOKIA. 



death of the foetus may be said to be the rule in shoulder presenta- 

 tions. With the smaller ruminants, owing to the formation of the pelvis, 

 birth is not often impeded. With the Sow and Carnivora — multiparous 

 animals — this might be designated a normal presentation. 



It will readily be perceived how one or both of the anterior members 

 bent back under the body, will prove an obstacle to the passage of the 

 foetus, after what has been said with regard to the relative dimensions of 

 the young creature and the pelvis of the mother. The shoulder or 

 shoulders, and the muscles in this region, are the cause of dystokia — 

 more especially the biceps brac/iii, which constitutes a thick and somewhat 

 tendinous elastic mass between the scapula and upper end of the fore- 

 arm. This muscular mass forms a very prominent obstacle on the side 



Anterior PresentatiOiV ; 



Fig. 114. 

 Both Fore-limbs Completely Retained. 



of the chest when the limb is thrown back. There is also the large 

 levator humeri muscle adding to the increased volume of the thoracic 

 region, as well as the elbow and fore-arm. 



On exploration in this complication, the head is found to be in a good 

 direction, the hand encountering it either in the pelvis or towards the 

 inlet^ or it may even protrude into the vulva, according to circumstances. 

 The foetus, if a calf, may be yet alive ; if a foal, it is nearly always dead. 

 If only one limb is completely retained, the other will be in a normal posi- 

 tion — alongside or under the head (Fig. 113). If both limbs are retained, 

 though the head may appear in the genital canal or at the vulva, yet 

 nothing can be discovered of the legs in the pelvis, they being entirely 

 lodged in the maternal abdomen. At each pain the head of the foetus is 

 propelled outwards, but as soon as this ceases it recedes again, as if 

 thrown back by a spring. 



With small-sized Cows, the hand introduced deeply into the uterus may 



