Likely as not, if you have a fat horse you have a horse with other problems as well. Laminitis, for example, can become a chronic issue with overweight horses and little makes a horse as unhappy as sore feet all the time.
Technically, issues with fat horses are being lumped together under the umbrella of “Equine Metabolic Syndrome.” Several specific problems such as poor reproductive performance, insulin resistance, and founder, can fit under the EMS umbrella, explained Simon Peek, clinical professor, UW-Madison School of Veterinary Medicine.
“This is not Cushing’s Disease,” Peek said. “EMS tends to affect horses much earlier in life; before they are 10 years of age. Cushing’s comes along much later in life.”
The term “easy keeper” is used to refer to a horse that seems to gain weight regardless of what or how much is being fed. But such animals probably have some type of EMS. Much of the blame for fat horses and “pasture inspired founder” was attributed to lush pastures. Pasture and diet have a role, but Peek said EMS is a much broader problem.
Some breeds of horses are more susceptible to EMS, for example. Ponies, Morgan, Arabians, Paso Finos and Saddlebreds are known to gain weight and develop laminitis. Any breed of horse can develop EMS, he added, but some are just more known to have such issues.
All tied together, EMS is a combination of diet, exercise, and genetics. An EMS horse is easy to spot with its crested neck, rounded body, and layers of dimpled fat over the rump above the hip. Isolating the specific nature of the EMS should involve an exam that includes testing blood glucose levels, radiographs of the hooves, and body condition scoring – a system for visually determining obesity and tracking change over time.
“There are four or five university groups looking into more advanced diagnostics,” Peek said. “The emphasis for controlling EMS is on management, because there is no specific drug therapy available.”
Once the horse’s feet are comfortably recovered from laminitis, the next phase of EMS management is exercise. A minimum of two to three hours a week of exercise is required. “And it’s better if you provide the exercise in a series of 20 or 30 minute episodes over the course of the week,” Peek said.
People seem to quickly grasp the idea of providing more exercise, Peek said, but don’t always want to buy into diet and pasture management. “Some horses shouldn’t be on pasture and to a lot of people that seems cruel,” Peek said. “But if you want the horse in the future, you have to learn how to manage pasture and diet.”
For the EMS horse, soluble carbohydrates are the enemy. Pasture, especially unlimited lush pasture, produces soluble carbohydrates in abundance. Anything sweet or high in carbohydrates is a threat. For the EMS horse, it’s 1.5 lb of grass hay per 100 lb of horse body weight.
People who use forage analysis are looking for a grass hay with less than 10 percent soluble carbohydrate. “You can reduce the carbohydrate challenge in some hay by soaking it in water for six or eight hours,” Peek mentioned.
Good grass hay, restricted pasture, increased exercise and a recommended mineral/vitamin supplement will go a long way toward maintaining the easy keeper in good health. Under the right management, Peek said you should be able to use and enjoy your horse for many years.