Malunion of an In Utero Metacarpal Fracture in a Standardbred Mare Presenting for Dystocia

In utero fracture and malunion of long bones is a rare condition in horses. Most foals with in utero fractures are aborted, and the identification of a fetal in utero fracture in a mare with dystocia has not been reported. A 7-year-old multiparous Standardbred mare presented to a referral center for correction of dystocia. Assisted vaginal delivery and controlled vaginal delivery attempts were unsuccessful mainly because of contracted tendons impeding mutation. As the foal was alive, a cesarean section was elected. The foal was delivered but ultimately euthanized because of the congenital abnormalities. Computed tomography of the right forelimb of the foal along with gross examination and histologic evaluation of the right metacarpus revealed the malunion of a previous in utero fracture. While a few cases have been reported of in utero fracture, many of these were in abortuses and not in fetuses at term, making this case a new presentation and potential etiology for dystocia. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

In utero fracture and malunion of long bones is rare in horses, often leading to abortion. This case presented a live foal with previous in utero fracture malunion, ultimately euthanized due to congenital abnormalities, shedding light on a new potential etiology for dystocia.