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

This research paper reports a rare case where a Standardbred mare suffered dystocia due to a malunion of an in utero fracture in the foal, necessitating a cesarean section. The foal was ultimately euthanized due to congenital abnormalities.

Introduction and Case Presentation

• The paper highlights a rare case of in utero fracture and malunion in horses, which is significantly uncommon as most foals with in utero fractures tend to be aborted.
• The case involves a 7-year-old multiparous Standardbred mare presenting to a referral center for correction of dystocia, a condition describing difficulty in giving birth.
• Despite attempts at assisted vaginal delivery and controlled vaginal delivery, the procedures were unsuccessful primarily due to the presence of contracted tendons in the foal that impeded mutation.
• Given that the foal was alive, the decision was made to perform a cesarean section.

Findings and Conclusion

• The foal, despite successful delivery, was eventually euthanized due to the presence of congenital abnormalities.
• An elaborate examination of the right forelimb of the foal was conducted. This included a computed tomography scan, a gross examination, and a histological evaluation of the right metacarpus (a long bone in the forelimb).
• The examination revealed the malunion of a previous in utero fracture in the foal.
• The paper underscores that while there have been a few reported cases of in utero fracture, most of them occurred in aborted foals and not in those at term. This makes the current case unique and a new potential cause of dystocia in mares.

Implications

• The study provides valuable insights into a new form of dystocia etiology that vets and breeding farms need to be aware of to minimize mortality and morbidity rates.
• Further research might be required to understand the real pathophysiological mechanisms at play, leading to in utero fractures and their contribution towards dystocia in mares.