Question

I read a lot of articles that warn against keeping horses too fat. I was a teenager when Secretariat won the Triple Crown in 1973, so I’ve been around horses for a long time, and I’ve kept plenty in “spare-tire condition” with seemingly no ill effects. Is this just an angle for vets and feed companies to sell more goods and services?

Answer

While many core aspects of horsemanship remain unchanged since Secretariat’s Triple Crown triumph, veterinarians and nutritionists have at their disposal a wealth of data that suggests chronically obese horses and ponies are at risk for health problems.

Aside from the orthopedic problems connected with obesity, namely osteoarthritis and laminitis, overweight horses often have trouble meeting performance expectations. They typically lack the agility and stamina of their fitter peers, and they are frequently intolerant of heat and humidity, especially at the beginning of a training protocol.

Certain endocrine and metabolic problems are unequivocally connected to obesity. Potential problems include equine metabolic syndrome (EMS), insulin resistance, and hyperinsulinemia, among others. Once these problems take hold, management becomes more difficult, usually necessitating special strategies, such as use of a grazing muzzle, restricted turnout, near-daily structured exercise, and stringent hay selection. Even more worrisome, however, is that some metabolic horses seem to be more susceptible to laminitis, hoof abscesses, and skin disease than healthy horses.

Without question, scientific evidence underscores the value in keeping horses in moderate body condition. Veterinarians and feed companies are therefore responding to the challenge thrust upon them, primarily to provide horse owners with research-proven solutions to manage their horses appropriately.

On the flip side, many horses show no changes in physiological or metabolic status despite obesity, and perhaps this is why you have not experienced any problems. Researchers are considering why some obese horses seem protected against the development of metabolic dysfunction and others are not.