ABNORMALITIES IN THE PARTURIENT PASSAGES 171 



must correspond with the diameters of the pelvis, in order to 

 have natural parturition. A pelvic constriction, quite fre- 

 quently observed in practice, is found in the juvenile pelvis. 



It is occasionally met with in two-year-old heifers, in 

 primiparse ; that is, at an age when they bear young the first 

 time. This pelvis is laterally constricted, especially in the 

 lower half. Relations between the transverse and vertical 

 diameter of the pelvic inlet may be normal, but the distance 

 between the pectineal tubercles, and especially between 

 the two cotyloid cavities, is lessened. As a consequence the 

 pelvic canal is narrow and renders the passage of the calf 

 difficult. 



Symptoms and Prognosis. — In this pelvic constriction, the 

 head, resting on the fore legs, passes the pelvic inlet, but the 

 withers and shoulders do not enter the pelvis. Parturition has 

 advanced to that point where the head and fore legs, the latter 

 slightly retracted, are visible at the vulva. Should the act of 

 birth have lasted already several hours, the fcetus is mostly 

 dead and the swollen tongue protrudes from the mouth. The 

 attendant, as a rule, has practiced extraction unsuccessfully and 

 the veterinarian on arrival finds head and legs firmly wedged 

 in the pelvis. 



The calf in itself may be of normal size, but is relatively 

 too large for the pelvic dimensions of the mother. 



The prognosis as regards the calf is unfavorable. It is 

 rare to see the calf live after extraction, provided it can be 

 removed as a whole. 



With regard to the mother, the prognosis is more favor- 

 able, unless the attendant exerted powerful traction. It can be 

 said that in general such a heifer stands a forcible extraction 

 astonishingly well. 



At this age the pelvis is not yet completely ossified, being 

 slightly dilatable. Stretching of the symphysis at that age in 

 the heifer is more quickly repaired than in the adult or old cow. 

 Many owners, who never permit severe traction on the calf, 

 base their experience on the extraction of a calf in a young cow 

 by five or six men. The juvenile pelvis does not interfere with 



