Rules for Managing the Overweight Horse

 By Juliet M. Getty PHD

Like a person, a horse has his own metabolic rate and genetic tendencies. Add in lack of exercise, too many treats, overfeeding, and stress, and the easy keeper becomes an overweight horse at risk for hormone imbalances, arthritis and laminitis.

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 fi rst 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 fi ne, but taking away forage is not the way to help your horse lose weight. In fact, it does just the contrary. For the most part, healthy horses become obese because they are

Like a person, a horse has his own metabolic rate and genetic tendencies. Add in lack of exercise, too many treats, overfeeding, and stress, and the easy keeper becomes an overweight horse at risk for hormone imbalances, arthritis and laminitis.

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, fl ax 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 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. The free-choice adjustment for stabled horses 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 freechoice, 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 hay only 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 eight 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.

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.