Calls for owners to use science-backed colic information over ‘old wives’ tales’

Maximising turnout may reduce the risk of post-partum colic in broodmares – as researchers call for owners to use science-backed information over “old wives’ tales”.

In a study published in Animals, researchers from the University of Liverpool investigated risk factors for post-partum colic in thoroughbred broodmares in the UK and Ireland. The researchers analysed medical and management data for more than 1,000 mares from 29 studs during the 2021 and 2022 foaling seasons.

Lead researcher Elizabeth Cullen, an equine internal medicine specialist at Rainbow Equine Hospital, told H&H it is known anecdotally, that broodmares are “very prone to developing colic” and that they are “widely regarded to be at an increased risk compared to other horses”.

“From the mares we followed we gathered lots of information about the colic episodes and diagnosis, any changes in management, medications, whether they had had colic before – and then we compared the data with three control horses: mares that had foaled but hadn’t got colic,” said Dr Cullen.

“The vast number of colic episodes were within the first 10 days. The risk of colic decreased from the point of foaling until around 50 days after, then plateaued.”

The findings showed that days post-partum and hours stabled had the “strongest associations with colic risk”; the likelihood of post-partum colic “increased by around 16% for each additional hour that mares were stabled per day”. Broodmares who had been given non-steroidal anti-inflammatory drugs (NSAIDs such as bute) in the previous 28 days or had a history of colic may be at increased risk.

“There’s plenty of reasons why less turnout and more time in the stable might cause colic; they’re not active, they’re not grazing and they’re being fed in more intermittent large quantities, which is not their natural feeding behaviour,” said Dr Cullen.

“In terms of bute use, we would need to look at why they were having bute, for example was the mare in more pain after foaling and actually predisposed to colic. It’s important to take findings at face value and the message is certainly not: ‘Don’t give them bute’, but that maybe these mares might be the ones to watch.”

Dr Cullen added that the research highlighted a need for further colic education among horse owners. In May H&H reported a University of Nottingham study that showed misconceptions around colic were common and that many owners were reluctant to change their approach.

“There were management strategies employed by studs where they had the perception ‘this would stop their horses getting colic’ – and a lot of things that they thought were important had very little evidence behind them,” said Dr Cullen, giving the example of feeding bran mash.

“There’s no evidence that bran mash is beneficial and it’s such a widely used strategy. Old wives’ tales get passed down, we had farms that would let their mares roll after foaling in the paddock if they thought that would stop them getting a twisted gut, or they put them on a special diet and change their feed. Colic is a huge emotional and financial strain and it’s important to disseminate information based on science.”

British Equine Veterinary Association junior vice-president James Crabtree told H&H the paper is a “welcome addition” to literature on post-foaling colic.

“We now have some helpful numbers quantifying the risk of encountering colic at this time, and how days post-foaling and confinement to the mare’s box influence her risk,” said Dr Crabtree, an equine reproduction and stud medicine independent veterinary consultant.

“With this improved understanding, we veterinarians can better communicate these risks to our clients to develop appropriate strategies to minimise the risk of post-foaling colic. In addition, it reveals some additional risk factors such as administration of non-steroidal anti-inflammatories in the preceding 28 days.”

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