776 Veterinary Obstetrics 



e. Dystokia in the Anterior Presentation due to the 



Forward Extension of the Hind L,imbs 



Beneath the Fetal Body. 



In the mare, and possibly in other animals, we occasionally 

 encounter a fetus presenting anteriorly, with the anterior limbs 

 and head in an approximately normal position, and the two 

 posterior limbs thrust forward in extreme extension beneath the 

 body of the fetus, so that the two hind feet are lodged just in 

 front of the maternal pubic brim, or have passed some distance 

 along the pelvic canal. This places the fetal body in such a 

 position that its progress becomes blocked when the neck or chest 

 has appeared at the vulva. 



Fig. 134. Forward Deviation of Posterior Limbs 

 IN Anterior Presentation. (St. Cyr. ) 



The nature of this presentation suggests to one that of the 

 ventral transverse presentation, in which all four feet are present, 

 but the head is wanting, whereas in this case all four feet and . 

 the head offer at the inlet, and become more or less engaged in it. 



The fetus is ordinarily in the dorso-sacral position, with the 

 proper relations existing between the two anterior limbs and the 

 head and neck. However, when it has advanced sufficiently for 

 the fore feet and nose to show at the vulva, its further progress 

 becomes blocked. Inserting the hand beneath the body of the 

 fetus, the operator encounters one or both posterior feet, either in 

 the pelvic canal or just anterior to the brim of the pubis, where 

 they are easily recognized, their soles directed downwards. The 

 spinal column is jammed hard against the maternal sacrum. 



