It's no secret that equine obesity is a growing problem. But what makes some horses more likely to be overweight than others, and just how many horses could stand to lose some weight? A team of British researchers set out to answer those questions in a recent study.

An obese or overweight horse is at risk for certain health conditions such as insulin resistance and laminitis. And, due to the subjective nature of determining how much fat horses have on their bodies, owners tend to underestimate body condition scores. Thus, the actual prevalence of obesity in the equine population remains fairly unknown.

To better enumerate the obese equid population in Great Britain and identify possible risk factors for obesity, Charlotte Robin, a research assistant at the Animal Health Trust in Newmarket, England, and colleagues randomly selected 792 owners of horses and ponies registered with 30 veterinary practices in Great Britain to complete a questionnaire by mail during a two-year study.

Owners were asked to estimate their horse's or pony’s body condition score (BCS) based on a modified version of the Carroll and Huntington scoring system, which evaluates the equid’s fat cover based on a scale ranging from zero (very thin) to six (very fat). The researchers categorized the horses and ponies as obese if the owners scored them a five or six