In theory, weight management—for both people and horses—is simple, said Tania Cubitt, PhD: Eat less, exercise more, and lose weight.

Nonetheless, obesity remains a problem for not only horses but the people who care for them as well. Approximately 70% of American adults are either overweight or obese, she reported, noting that recent studies in horses have found obesity in 32% to 62% of animals. So if the weight management concept is that simple, she asked, why isn’t it working?

Cubitt, an equine nutritionist for Performance Horse Nutrition in Weiser, Idaho, presented a lecture on ways to manage equine obesity at the 2013 Alltech Symposium, held May 19-22 in Lexington, Ky.

Obesity has a number of causes, Cubitt said, ranging from genetics to improved forage quality (horses didn’t evolve eating bright green grass, she noted; rather, they consumed sparse, high fiber forage) to a lack of exercise. And it’s at the root of a number of serious health problems, including insulin resistance, chronic inflammation, oxidative stress, and possibly even a decreased life span.

In fact, she noted, obese horses often face more health challenges than very skinny ones. Considering that, managing and preventing obesity should be at the top of every horse owner’s to do list, she said.

But one of the major problems contributing to equine obesity, Cubitt said, is the owners themselves.

"Owners significantly underestimate the weight, body condition score (BCS), and cresty neck score of the horse," she said. They also tend to have misconceptions on a number of important weight-related factors, includi