Top Tips for Safe Equine Weight Loss

Equine obesity significantly impacts horse welfare, leading to health problems such as metabolic disorders and an increased likelihood of joint disease. Given the nature of horses and their foraging behavior, promoting weight loss is often not as simple as feeding them less, although that is part of the equation. Additional dietary changes and increased exercise also encourage safe equine weight loss.
The Prevalence of Equine Obesity
“Obesity is considered a multifactorial disease that occurs when a horse consumes more energy than it expends, leading to fat accumulation,” says Alex Rankovic, PhD, postdoctoral research fellow in companion animal and equine nutrition at the University of Guelph, in Ontario, Canada. Researchers estimate over 50% of the equine population in the U.S. is overweight.
“This is highly concerning as many owners don’t realize the ticking time bomb that obesity is within the equine body,” says Rachel Mottet, PhD, equine nutritionist and owner of Legacy Equine Nutrition, an independent equine nutrition consulting business based in Ocala, Florida. “We are playing with fire (i.e., our horses’ health and longevity) by allowing our horses to become and live in an obese state.” Excessive weight on a horse’s body can increase the strain on his joints, leading to more severe joint disease, and might increase his risk of metabolic disorders, making him more prone to developing laminitis.
Risk Factors for Equine Obesity
Rankovic notes that several risk factors contribute to equine obesity, including genetic predisposition, excessive nutritionally rich feed and lack of exercise and owner awareness of ideal body condition score (BCS).
“Based on my conversations … I feel like owners don’t always realize that hay and pasture deliver calories that can cause weight gain in their horses,” says Mottet. “Not all horses become overweight or obese on high-quality pasture or hay but, keep in mind, horses have unique metabolic qualities and genetic predispositions that lead to different body condition outcomes in a herd on the same diet.”
Mimicking a horse’s natural grazing behavior plays a crucial role when promoting a healthy weight and improved gastrointestinal health in your horse. Horses thrive on consistent fiber, which can make restricting their feed for weight loss challenging. “This can be a bit confusing as one might wonder why the domesticated horse becomes obese on the diet that their ancestors thrived on,” says Mottet. “The things we don’t always think about—the quality of the hay we feed horses often greatly surpasses what’s available in the wild, horses in the wild (are) more frequently on the move, horses in the wild go through seasons where quality forage is scarce.”
Top Tips for Safe Equine Weight Loss
1. Assess your horse’s BCS frequently.
It can be challenging for owners to pinpoint the ideal BCS for their horses. “Part of this is not knowing how to use the body condition scoring system, which I can understand, as it is difficult to do if you’re not using it regularly,” says Mottet. “Another issue is what we see from others is what we think is correct—and with an estimated 50% overweight horse population, there’s a good chance most owners think overweight is the ideal.”
A horse owner can track a horse’s body condition and weight in a variety of ways, including performing a BCS check every two to four weeks. “While weighing the horse with a scale is ideal, it is often not feasible for most owners,” says Rankovic. “In such cases, a weight tape is an affordable tool that can be used to estimate weight. When using a weight tape to track changes over time, it’s important to ensure consistent conditions using the same tape in the same spot, ideally measured by the same person. In addition to monitoring weight, using the Henneke BCS, which ranges from 1 (emaciated) to 9 (obese) allows owners to perform a visual assessment and hand palpation of fat coverage in six key areas. The ideal BCS typically falls between 4 and 5, although this will vary depending on the horse’s discipline, performance level, or reproductive status (i.e., broodmares).”
2. Measure your horse’s daily forage intake.
Reducing your horse’s forage intake to less than 1.5% of their body weight often results in further health issues. “Find a way to weigh the hay that your horse is eating each day,” says Mottet. “My goal is always to keep the forage maximized to the greatest extent possible. I like to keep hay intake around 1.5% of the horse’s body weight per day, even when on a diet. Slow-feeder systems can then be incorporated so it takes the horse longer periods of time to eat less, mimicking the natural eating habit.”
3. Remove unnecessary supplemental calories from your horse’s diet.
Overweight horses generally only need a ration balancer or a vitamin/mineral premix to supplement their forage. “Eliminating calorie-dense concentrates, supplemental oils, and excessive treats is an important step,” says Rankovic. “Research has shown that even small amounts of concentrate can increase the likelihood of obesity, particularly when these feeds are given as treats rather than out of necessity.”
4. Evaluate the energy content of your horse’s forage.
For some horses, hay with high energy content (calories) might increase their risk of obesity. If possible, partially or fully replace this high-calorie, early maturity hay with a later-maturity option, says Rankovic. Have the hay analyzed and offer it at 1.5% to 2.0% of the horse’s body weight, depending on its energy density and digestibility and the horse’s current body condition.
You can also reduce the energy content of your horse’s hay by soaking it before feeding. For horses with severe obesity, an equine nutritionist might recommend replacing up to 25% of the hay with clean, chopped straw to reduce their caloric intake without reducing their time spent foraging, says Rankovic. However, straw should be introduced gradually, and care must be taken to supplement the horse with salt to encourage drinking and provide free-choice access to water to reduce the risk of impaction colic, she adds. Consult your veterinarian or an equine nutritionist before making drastic changes to your horse’s forage intake.
5. Increase your horse’s exercise.
Exercising your horse more in conjunction with dietary changes can improve his weight loss. “If the horse is sound to do so, increasing the amount of exercise and the intensity of each workload is recommended,” says Mottet.
“For horses not exercising, starting with two to three exercise sessions per week, each lasting 20 to 30 minutes, is recommended,” adds Rankovic. “As the horse’s fitness improves, gradually increase the exercise intensity and duration.”
Take-Home Message
Obesity can cause serious health issues such as metabolic dysfunction, which can result in the painful condition laminitis. Carrying extra weight can also lead to joint disease and damage. Focus on quantifying your horse’s weight and forage intake to help your horse begin to lose weight. Remove unnecessary supplemental feeds, while still providing a low-calorie source of vitamins and minerals, and consider increasing his exercise load, if he is sound to do so. Work with your veterinarian during this process to ensure the changes are suitable for your horse and promote safe equine weight loss.

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