NEW research involving Ballylinch Stud in Co Kilkenny has provided valuable insight into why some thoroughbred broodmares may be more susceptible to colic in the weeks following foaling.

The study, published in the Equine Veterinary Journal in June 2026, followed 1,044 thoroughbred mares across 29 stud farms in Britain and Ireland over two foaling seasons.

Led by European Specialist in Equine Internal Medicine, Dr Lizzie Cullen, with researchers from the University of Liverpool and with Ballylinch Stud’s accomplished resident vet, Dr Jennie Henderson, the study investigated a range of horse and management-related factors that might increase, or decrease, the likelihood of post-partum colic.

Every additional hour

A total of 39 episodes of colic were recorded during the study period, with the risk greatest immediately after foaling and decreasing over approximately the following 50 days.

One of the most interesting findings concerned stabling.

Researchers found that the likelihood of colic increased as the number of hours mares spent stabled each day increased. For every additional hour spent in the stable, the odds of developing post-partum colic increased by approximately 20%.

The finding has obvious practical relevance for breeders, as management frequently changes around foaling. Mares may spend considerably more time indoors as their due date approaches and during the early days of their foal’s life.

Reduce colic risk

The researchers suggest that, where conditions allow, maximising turnout during the post-partum period could therefore be one relatively straightforward way of helping to reduce colic risk.

Dr Henderson told Horse Sense: “A theme emerges in common with another recent study, headlined ‘Born to Run’, by Rebecca Mouncy and colleagues, which showed how increased daily turnout time and acreage in the first six months of life was associated with increased likelihood of racing.

“Turnout is good for mares and foals: a refreshingly concise take home message for busy farmers and vets whose only spare moment to catch up on news might be the time it takes to grab a quick cup of coffee.

“My great grandad could have told us that”, I hear some say… which leads to a second take home message; the importance of collaborations which combine the research expertise from the universities with the ‘real life’ situation on the farm.

“As farmers and vets, we know that keeping good records helps us look for trends, trouble-shoot, strive for improvement.”

For those with more time, Ireland is excited to host the International Symposium on Equine Reproduction, in Dublin next August, bringing cutting edge research to share with breeders and vets.

Also in the study, previous colic history was another important factor. Mares that had suffered colic previously were significantly more likely to experience an episode following foaling.

Decisions around turnout

Recent use of non-steroidal anti-inflammatory drugs, such as Bute (NSAIDs), was also associated with increased colic risk. However, the researchers caution against interpreting this as evidence that the medication itself caused colic. Mares receiving NSAIDs may have had underlying illness or other circumstances that independently increased their risk. Calcium supplementation was also associated with increased risk in one statistical model, although the finding was not consistent across both models used in the analysis.

The researchers emphasise that their findings demonstrate associations rather than proof of cause and effect. Decisions around turnout must also take account of the individual mare and foal, weather, paddock conditions and veterinary considerations.

Nevertheless, the scale of the study provides useful real-world evidence from commercial thoroughbred breeding operations. For breeders, perhaps the clearest message is also one of the simplest: during the weeks following foaling, keeping mares moving and maximising safe access to turnout may be an important part of reducing their risk of colic.