Etiology survey of some cases of bovine clinical dystocia

In order to study the etiology of bovine dystocia، the records of 255 cases of dystocia referred to the university veterinary hospital in Ahwaz، Urmia and Shiraz over a 20 year period were analyzed. Of these mixed local breeds of cows 80 (31. 4%) were first calvers، 48 (18. 8%) second calvers، 45 (17. 6%) third calvers، 43 (16. 9%) fourth calvers and 39 (15. 3%) fifth or more calvers respectively. One hundred and ten cases (43. 1%) had dystocia with maternal origin، 127 (49. 8%) cases had dystocia of fetal origin and 18 (7. 1%) of the cases had both feto-maternal origin dystocia. Of the maternal dystocia cervical dilation failure and uterine torsion were most abundant and with the exception of uterine inertia، all had a highly significant negative correlation with the maternal parity. Cervical dilation failure had a positive correlation with narrow pelvis and uterine torsion to the right. Of the fetal origin dystocia flexed posture and ventral position، followed by posterior presentation، were most frequent. Monsters were similarly found in all the groups. All these types of fetal dystocia were significantly correlated with maternal parity، and with the exception of vertical presentation and lateral position، all the types were significantly inter-related. These observations draw attention to the incidence of possible causes of dystocia and help to the management of these cases.