Reproductive careers of Thoroughbred broodmares before and after surgical correction of ≥360 degree large colon volvulus.
Authors: Leahy E R, Holcombe S J, Hackett E S, Scoggin C F, Embertson R M
Journal: Equine veterinary journal
Summary
Large colon volvulus (≥360°) is a life-threatening surgical emergency, yet little has been documented about reproductive outcomes for Thoroughbred broodmares who survive the operation and return to breeding programmes. Researchers at Rood and Riddle Equine Hospital analysed reproductive records from The Jockey Club for 584 mares that underwent surgical correction between 2000 and 2015, comparing their breeding performance before and after surgery. Mares with prior foaling success demonstrated resilience post-operatively, though with reduced output: they produced an average of 4.8 foals in the years before surgery compared to 2.6 afterwards, though their overall career longevity remained substantial. Critically, age at surgery emerged as the dominant prognostic factor—mares aged 3–11 years produced significantly more foals following recovery than those aged 12 years or older, whilst mares that had never successfully foaled before surgery had markedly shorter careers overall. For practitioners advising owners on surgical vs. conservative management decisions, this data suggests that younger mares with established breeding records represent the best candidates for intervention, as they retain meaningful reproductive potential post-operatively, whereas older or reproductively unproven mares face a less predictable outcome.
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Practical Takeaways
- •Broodmares can continue reproductive careers after surgical correction of large colon volvulus, but younger mares (under 12 years) have better post-surgical breeding outcomes
- •Expect reduced breeding productivity after surgery compared to pre-surgical performance, particularly in foal production rates
- •Mare age at time of colic surgery is the most important factor determining future reproductive success—younger mares should be prioritized for surgical intervention when indicated
Key Findings
- •Mares with prior foaling history had significantly longer breeding careers before surgery (5.9 ± 3.8 years) compared to after surgery (4.5 ± 3.3 years), P<0.001
- •Mares that foaled before surgery produced more foals pre-operatively (4.8 ± 3.0) than post-operatively (2.6 ± 2.4), P<0.001
- •Younger mares (3-11 years at surgery) produced significantly more foals after surgery than mares ≥12 years old, suggesting age at surgery is a major prognostic factor
- •Mares that were bred but never foaled prior to surgery had substantially shorter careers (4.4 ± 4.5 years) and fewer lifetime foals (3.1 ± 3.3) compared to those with prior foaling success