manage your horse's weight

Ironically, restricting your easy keeper’s feed can actually lead to weight gain! To manage his weight and prevent health problems, follow these seven rules instead.

It’s not your horse’s fault if he’s an “easy keeper”. Like a person, a horse has his own metabolic rate and genetic tendencies. Add in lack of exercise, too many treats, overfeeding, even stress, and the easy keeper is at risk for hormone imbalances, arthritis and laminitis. It should be no surprise that the overweight horse will not perform at his peak.

Metabolic Consequences

Too much fat leads to insulin resistance, a hormonal disorder also called metabolic syndrome. It’s like Type II diabetes in people, and equally serious. An insulin-resistant horse is a strong candidate for laminitis. Elevated insulin levels also can cause hyperlipemia, a damaging liver condition. Ponies, miniature horses, donkeys and mules are particularly prone to it, but no horse is immune.

Watch for fat accumulation above your horse’s eyes, on his rump, along his neck (“cresty neck”) or in a fatty spinal crease down his back. All overweight horses have some degree of insulin resistance, so feed the easy keeper on that assumption to be on the safe side.

Rules of Proper Weight Management

The first step in any weight management program is to have your horse thoroughly examined by your veterinarian, including a complete blood count and chemistry panel tests, to rule out any underlying medical disorders. Then take a hard look at your horse’s feeding and exercise regimens.

Rule #1: Avoid weight loss products and drastic diets. Reducing calories is fine, but taking away forage is not the way to help your horse lose weight. In fact, it does just the contrary (see opposite).

For the contrary most part, healthy horses become obese because they are given concentrated feeds – this includes products promoted for weight loss (which, in fact, add calories). Concentrates are no substitute for forage. Use them only as carriers for supplements, or to provide a small meal to satisfy your horse while others are eating.

Rule #2: Avoid feeding cereal grains and sugary treats. “Grain” is commonly used to describe any concentrated feed, but it really means cereal grains such as oats, corn, barley, wheat or pelleted feeds that contain cereal grains. Stay away from these. Fortunately, there are many safe low starch feeds made from other ingredients (alfalfa, soybean meal, flax and beet pulp).

The high sugar in carrots and apples increases blood insulin levels. Avoid them, as well as any commercial treats made from cereal grains and molasses.

Rule #3: Consider an all-forage diet. Depending on your horse’s age, workload and condition, an all-forage diet can be very healthful. You may not need to feed him any concentrate at all. But have your hay tested for sugar, fructan and starch levels. Strive for a non-structural carbohydrate (NSC) level of less than 12%.

Be careful when feeding high-calorie hay such as grain hays (oat, crested wheatgrass, rye) and grass/legume combinations (Timothy/alfalfa mixes). Alfalfa is a wonderful feed, but it’s higher in calories than grass, so limit it to no more than 20% of the total forage ration.

Alfalfa boosts the protein quality in the forage mix. High quality protein maintains immune function, protects the vital organs, keeps bones, muscles and joints strong, and builds healthy hooves, skin and hair. Low quality protein is unusable and can be stored as fat.

Rule #4: Feed free-choice. All horses, regardless of their weight condition, should have forage at all times. Yes, 24/7. Your horse’s digestive tract is designed to have forage moving through it consistently throughout the day. Horses on pasture self-regulate their intake.

Sure, your stabled horse “inhales” every speck of available hay now – he is storing up until his next feeding. So give him all he wants. The free-choice adjustment takes about a week, during which the horse may initially overeat, but he will soon trust the hay to be there, and will moderate his consumption. At that point, you can measure his regular intake to make other feed calculations. And look for a bonus: fed free-choice, horses generally become calmer and more tractable.

Rule #5: Choose safe grazing times. Grass has the lowest sugar, fructan and starch levels in the early morning. As it is exposed to sunlight, it produces more NSC, making the late afternoon the most hazardous time for the easy keeper. Grass is also more dangerous in the early spring and late fall when the thermometer dips below 40°F overnight; this also raises the NSC levels.

A grazing muzzle may seem ideal, but it can be counterproductive by causing stress and slowing the metabolic rate. So watch your horse; if a muzzle is frustrating him, it’s not helping.

Rule # 6: Offer a balance of vitamin/mineral supplements. Live grass offers an abundant supply of vitamins and minerals, but the nutrient content in hay diminishes over time. Minerals remain, but vitamins are very fragile, so hayonly diets require supplementation. Offer these in a small non-starchy carrier meal. Avoid supplements with a molasses base.

Most comprehensive products contain a balanced mixture of vitamins and minerals. If your horse’s diet contains more than 8 pounds of alfalfa, choose a supplement designed for alfalfa-based diets; it will be lower in calcium. A caution about iron: too much may increase insulin resistance as well as depress immune function. In any case, forage is iron rich, making supplementation unnecessary.

Three nutrients are commonly undersupplied:

•vitamin E, omega-3 fatty acids and magnesium.
• Magnesium helps lower circulating insulin levels, allowing your horse to burn fat rather than store it. Add enough magnesium to provide 5,000 mg per 250 pounds of body weight. If possible, have your hay analyzed first to see how much your horse is getting and then supplement the difference. • Aim for 1 IU of vitamin E per pound of body weight at maintenance; more if exercised. Vitamin E and selenium work together. However, selenium can be toxic at relatively low levels, so be sure to evaluate the selenium content of the total diet before supplementing. It should be no more than 1 to 3 mg total (maximum 5 mg, if in heavy training).
• Omega 3 fatty acids are necessary for proper immune function, joint health, and hoof and hair condition, and they also regulate blood insulin levels. Although high in fat calories, flaxseed meal in small quantities provides unparalleled support for your horse’s health.

Rule # 7: Add or increase exercise. Exercise reduces insulin resistance, builds muscle mass and burns more calories. And since muscle is more metabolically active than fat, more muscle means more calories burned.

Excess weight hinders the easy keeper’s quality of life. With just a little extra attention, you can help your horse achieve and maintain ideal weight, and with it, optimal wellbeing – and that is a gift sweeter than sugar.

Juliet M. Getty, Ph.D. has been called a “pioneer in free choice forage feeding,” and her articles and interviews often appear in national and international publications. Based in beautiful rural Bayfield, Colorado, Dr. Getty runs a consulting company, Getty Equine Nutrition, LLC (, through which she offers private consultations and designs customized feeding plans to promote horses’ health, reverse illness, and optimize performance. A former university professor and recipient of several teaching awards, she is a popular speaker, and is author of the book, Feed Your Horse Like a Horse, based on the premise that horses (and other equines) should be fed in sync with their natural instincts and physiology.


Dr. Juliet M. Getty earned her Master of Science degree in Animal Nutrition at the University of Florida. She completed her doctoral coursework in Animal Nutrition at the University of Georgia, and continued her studies at the University of North Texas, where she earned her PhD. Winner of several teaching awards, Dr. Getty has taught comparative nutrition studies at the University of North Texas for 20 years. At the same time, she has been working in the field, consulting privately with horse owners to customize feeding plans that address a variety of health conditions. Recently retired from academia, she now resides in Denton, Texas, where she devotes herself full-time to equine nutrition. Through her consulting company, Getty Equine Nutrition, she provides consultations locally, nationally and internationally.