246 BOVINE OBSTETRICS 



Iii fact, this presentation is a favorable one for large calves, 

 since by pulling on one leg the trochanters pass obliquely 

 through the pelvic canal, after which the other foetal dimen- 

 sions rarely form an obstacle ; but in the anterior presentation 

 the trochanters occasionally cannot pass the pelvic inlet after 

 one-half of the calf is born. 



When one or both hind legs are turned against the belly, 

 expulsion is in most cases impossible. It is only possible 

 when the calves are small or the pelvis wide. 



Causes. —Insufficient dilatation of the cervix uteri, incom- 

 plete rotation, respectively accommodation, at the pelvic inlet 

 in consequence of feeble pains, as seen in twin-pregnancy and 

 an excess of fcetal waters. Violent pains, with too early dis- 

 charge of the foetal waters, may also produce this malposition. 



One land leg retained, the fetlock lying below or against the 

 symphysis. 



Diagnosis.— The hind leg lies in the parturient passage, the 

 exterior surface of the leg is turned toward the floor of the 

 pelvis, the plantar surface of the claw is directed upward. 



The hand introduced into the vagina feels the fetlock 

 turned upward, and the tendo Achilles, further on the tail, 

 the postero-external angle of the ischium, below the gluteal 

 muscles, and the fetlock of the retained leg in front of the (in- 

 terior border of the pubis. 



When the owner exerts strong traction upon the hind leg 

 normally presented, its hock is found in the vulva and the 

 pelvis of the calf in the pelvic inlet. 



In this abnormal presentation the greater part of the foetal 

 waters are usually evacuated. 



Prognosis is favorable. 



Treatment.— Small calves, as seen in twin-pregnancy or 

 abortion, are occasionally extracted by the owner on the pre- 

 senting hind leg in spite of the malposition. In such a ease 

 the retained leg is firmly pressed against the belly and the 

 femur and tibia are extended on the long axis of the body. 



