Study identifies postpartum colic risk factors in broodmares
Bottom line
A new prospective study in Equine Veterinary Journal identified several risk factors for post-partum colic in UK and Irish Thoroughbred broodmares, adding data to a problem long recognized in breeding practice but not well quantified. Researchers followed mares on 29 stud farms in the United Kingdom and Ireland and recorded 39 colic episodes in 33 mares. Risk was highest immediately after foaling and fell by about 10% per day during the first 50 days post-partum. More time stabled was associated with higher risk, with each additional hour in the stable linked to a 16% increase in odds. Recent NSAID use and a prior history of abdominal pain were also associated with higher odds, while a calcium-based supplement appeared in one model but became non-significant when stud-level effects were considered. (beva.onlinelibrary.wiley.com)
Why it matters: For equine veterinarians and breeding-farm teams, the study offers practical signals rather than proof of causation. The clearest management takeaway is that post-foaling confinement may matter: industry coverage of the paper highlighted turnout as a potentially modifiable factor, while the authors cautioned that associations around NSAID use and calcium supplementation may reflect underlying illness or farm-specific practices rather than direct effects. Outside experts also note that broodmares are biologically vulnerable around foaling because abdominal space, hydration, and stress all shift quickly in this period. (theirishfield.ie)
What to watch: Expect follow-up discussion on how studs balance safe turnout, analgesic use, and mare monitoring in the first 50 days after foaling, and whether similar risk patterns hold beyond Thoroughbred operations in the UK and Ireland. (theirishfield.ie)
Key facts
- Study type
- Prospective nested case-control study
- Population
- UK and Irish Thoroughbred broodmares
- Study setting
- 29 stud farms in the United Kingdom and Ireland
- Cases
- 39 colic episodes in 33 mares
- Highest-risk period
- Immediately after foaling
- Risk over time
- About 10% lower odds per day during the first 50 days post-partum
- Stabling association
- Each additional hour stabled per day was linked to a 16% increase in odds
- Other associated factors
- Recent NSAID use and prior abdominal pain history
- Supplement finding
- Calcium-based supplementation was non-significant after stud-level effects were considered
A new Equine Veterinary Journal study puts numbers behind a familiar concern in broodmare medicine: the weeks after foaling are a higher-risk period for colic, and management may shape that risk. In a prospective nested case-control study of Thoroughbred broodmares on 29 stud farms in the United Kingdom and Ireland, investigators found that post-partum colic risk was highest immediately after foaling, then declined significantly over the next 50 days. They also found that more hours stabled per day, recent NSAID administration, and a previous history of abdominal pain were associated with increased odds of colic. (beva.onlinelibrary.wiley.com)
That matters because broodmares have long been considered a special-risk population, but the evidence base for why some mares colic after foaling has been thin. The paper notes that broodmares are known to be at increased risk of gastrointestinal colic, yet risk factors specific to this population had not previously been investigated in this way. Clinical commentary published by The Horse this month echoes that broader concern, pointing to stress, reduced abdominal space during pregnancy, and hydration changes as plausible contributors around foaling and breeding. Separate expert coverage has also emphasized the danger of large-colon volvulus in postpartum mares, when the sudden empty abdominal space after foaling may allow the colon to shift more easily. (beva.onlinelibrary.wiley.com)
The study itself was led by E. Cullen and colleagues at the University of Liverpool, with collaboration from Ballylinch Stud in Ireland. According to the paper, 39 colic episodes occurred in 33 mares, with 117 matched controls. In the model focused on time from foaling, the odds of colic fell by about 10% for each additional day up to 50 days post-partum. In the model focused on stabling, each additional hour stabled per day was associated with a 16% increase in odds. Recent NSAID administration within the previous 28 days was associated with higher odds in both models, and mares with a history of abdominal pain were also at increased risk. (beva.onlinelibrary.wiley.com)
One more finding drew attention, but with more uncertainty: calcium-based supplementation was associated with increased risk in one model, yet the paper says that association disappeared when stud was included as a variable, suggesting a farm-level management effect rather than a supplement effect per se. The authors explicitly say the true significance is unclear. That nuance is important, especially because calcium physiology has biologic plausibility in gut motility, but this dataset does not establish causation. (beva.onlinelibrary.wiley.com)
Industry reaction has centered on turnout. The Irish Field, reporting on the June 2026 publication, framed the study’s practical message as a case for maximizing safe pasture access when conditions allow. The article cited Dr. Jennie Henderson of Ballylinch Stud, who said the work reinforces the value of collaborations between university researchers and commercial farms, and described turnout as good for mares and foals. Another recent trade report similarly highlighted increasing confinement after foaling as a key management signal for breeders and veterinarians. (theirishfield.ie)
Why it matters: For veterinary professionals working with breeding farms, this is useful because it separates modifiable management signals from less actionable background risk. Prior colic history is a flag for closer surveillance. More intensive stabling may warrant a harder look at turnout protocols, exercise, hydration, and feeding transitions in the immediate post-foaling period. At the same time, the NSAID association should not be overread as a medication warning on its own; the authors note it may simply mark mares already dealing with pain or illness. For veterinarians advising pet parents involved in breeding operations, the message is not “avoid NSAIDs” or “blame supplements,” but rather “audit the whole postpartum management picture, especially in the first 50 days.” (beva.onlinelibrary.wiley.com)
The study also offers a benchmark for practice conversations. A University of Liverpool repository summary of the broader work noted that postpartum broodmares in this research appeared more likely to develop severe colic than the general UK horse population, with a high proportion referred for hospital care and many requiring exploratory laparotomy. While that summary is secondary to the journal article, it helps explain why even relatively small shifts in risk matter operationally on stud farms. (livrepository.liverpool.ac.uk)
What to watch: The next question is whether these findings translate into formal management guidance, especially around turnout and postpartum monitoring, and whether future studies in other breeds, geographies, or breeding systems confirm the same pattern. The current paper is strongest as real-world epidemiology from commercial Thoroughbred farms, and its most durable takeaway may be that the first seven weeks after foaling deserve especially close, structured attention. (beva.onlinelibrary.wiley.com)