Mare and foal survival and subsequent fertility of mares treated for uterine torsion.
Authors: Spoormakers T J P, Graat E A M, ter Braake F, Stout T A E, Bergman H J
Journal: Equine veterinary journal
Summary
# Editorial Summary: Uterine Torsion Correction and Reproductive Outcomes in Mares Uterine torsion remains a life-threatening emergency in pregnant mares, yet uncertainty persists about which surgical approach—standing flank laparotomy (SFL), midline laparotomy under general anaesthesia, or vaginal correction—yields the best outcomes for both dam and foal. Spoormakers and colleagues conducted a retrospective analysis of 189 clinical cases from three Dutch referral hospitals across two decades, examining survival rates, recovery timelines and subsequent fertility according to both surgical technique and gestational stage. Overall results were encouraging (90.5% mare and 82.3% foal survival), but multivariable analysis revealed critical nuances: for foals, SFL dramatically outperformed alternative methods (88.7% versus 35.0% survival; P = 0.001), with gestational stage also playing a significant role—cases corrected before day 320 had 90.6% foal survival compared to just 56.1% at or beyond this point. For mares, SFL showed decisive superiority only before day 320 (97.1% versus 50.0% survival), whilst outcomes between techniques converged at later gestations (both ~70–76%). Importantly, of 123 mares subsequently bred, over 93% became pregnant regardless of correction method, indicating that post-operative fertility is not compromised. These findings support SFL as the preferred technique for uncomplicated torsion in most cases, though practitioners managing torsions beyond day 320 should recognise that alternative surgical approaches may be equally appropriate for dam survival, even if foal prognosis remains guarded.
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Practical Takeaways
- •Standing flank laparotomy should be the preferred surgical technique for uncomplicated uterine torsion in pregnant mares, particularly when gestation is <320 days, as it significantly improves both foal and mare survival rates
- •Earlier intervention in gestation (before day 320) substantially improves foal survival outcomes, emphasizing the importance of early diagnosis and prompt treatment
- •Mares successfully treated for uterine torsion maintain excellent subsequent fertility regardless of correction method used, making salvage treatment worthwhile from a breeding perspective
Key Findings
- •Standing flank laparotomy achieved 88.7% foal survival compared to 35.0% with other correction methods (P = 0.001)
- •Mare survival after SFL was 97.1% at <320 days gestation versus 50.0% with other methods; no difference at ≥320 days (76.0 vs 68.8%)
- •Foal survival was 90.6% when UT occurred before day 320 versus 56.1% at ≥320 days (P = 0.007)
- •Of 123 mares bred after treatment, 93.5% became pregnant with no significant difference between correction techniques (93.9% SFL vs 87.5% other; P = 0.9)