Weight Gain More Than Doubles a Horse’s Laminitis Risk

Horses and ponies that gain weight are more than twice as likely to develop laminitis than if they lose or maintain their weight, a recently published study revealed.

Carried out by researchers from the Animal Health Trust (AHT), Rossdales Equine Hospital, and the University of London’s Royal Veterinary College, all in England, the study also revealed the groups particularly at risk were British native pony breeds and their crosses, as well as horses and ponies with a history of laminitis and those with lameness or soreness after routine hoof care.

This research, funded by equine charity World Horse Welfare, comes from the first ever online study that collected information from a group of horse and pony owners in real time. The study is also the second largest to identify weight gain as a risk factor for laminitis. Owners of 1,070 horses and ponies in Great Britain regularly reported their animal’s management, health, and estimated weight via online questionnaires for 29 months. The findings highlight how important regular weight monitoring is to prevent negative impacts on an animal’s health, the researchers said.

The research team encouraged owners to use a custom weight tracking tool they designed to help document changes in their animal’s weight and body condition. The uptake of this tool was high, with over half of participating owners using it, the team reported.

Other key findings included:

• A high risk of laminitis was present in horses shod or trimmed at intervals of more than 8 weeks, and in those that took a long time to return to soundness after a bout of laminitis.
• Diet, grazing management, and health were factors closely associated with laminitis development and will be the subject of future investigation. Investigation subjects will include, for example, investigating how short-term access to grass in the morning and part-time use of grazing muzzles might contribute to laminitis development.
• Weight gain often occurred unintentionally, even when owners were aiming for their animals to maintain or lose it. This reiterates the need to consistently record weight and body condition in order to prevent undesirable weight gain.

“This is one of the largest, and the first, online laminitis studies where we collected regular information from the same group of owners in real-time,” said Dee Pollard, BSc, BSc (Hons), MSc, PhD, a postdoctoral research scientist focusing on epidemiology and disease surveillance at the AHT, and one of the study’s chief authors. “We assessed the relationship between laminitis and many potential management and health factors and identified those more likely to be present before a laminitis episode was reported. We now have good evidence to develop laminitis prevention guidelines, and a number of different avenues to explore in the future.

“We cannot emphasize enough how important systematic and regular weight and body condition monitoring are,” she added. “It’s very easy to miss weight gain when you are just relying on your eyes and you see your horse or pony every day. You need to get hands on, feel for the fat deposits, and take measurements. Remember, the figures don’t lie.”

The study, “Identification of modifiable factors associated with owner-reported equine laminitis in Britain using a web-based cohort study approach,” was published in BMC Veterinary Research.