Horses are inheritably couch potatoes. An overeating, slothful horse leads to an obese horse. Unlike humans, however, horse owners often don't see the dangers of an obese horse. Caretakers may see no harm in giving their horses rich foods, but obesity in horses is just as unhealthy as obesity in humans and can lead to fatal diseases.
"There is a striking parallelism between humans and horses when it comes to obesity," said Philip Johnson, professor of veterinary medicine and surgery at the University of Missouri-Columbia. "Some of the very same problems humans encounter with obesity may also occur in horses."
Obesity in horses not only causes weight gain but also endocrine problems, including insulin resistance. The equine obesity risks have been less studied, but researchers believe horses have similar risks as humans, such as heart disease and diabetes.
Obesity in horses also can cause laminitis, a painful condition that often affects the front hooves. The weight of the bone is suspended in the hoof with connecting tissue forming a structure similar to a swing on a swing set. The extra weight in obese horses forces the connective tissue to tear and the bone breaks through the nail-like texture of the hooves. Veterinarians have yet to find an effective treatment for the condition. In the worst cases of laminitis, veterinarians are forced to euthanize the horse. Horses that develop insulin resistance are at an increased risk for laminitis, Johnson said.