Feeding an EMS Horse: A Low-Sugar Diet Guide
How to feed a horse with equine metabolic syndrome: low-NSC forage, soaking hay, restricting grass, safe balancers, and protecting an insulin-dysregulated horse from laminitis.
Feeding a horse with equine metabolic syndrome (EMS) comes down to one central goal: keeping sugar and starch low enough that insulin stays under control and the feet stay safe. EMS is built on insulin dysregulation, where the body overreacts to non-structural carbohydrates (NSC), and that high insulin is what drives the laminitis these horses are so prone to. Get the diet right and most EMS horses live comfortable, sound lives. Get it wrong and a single sugar spike can put them in the hospital.
This guide walks through the low-sugar diet step by step: forage first, balancing without grain, managing grass, and adding calories safely on the rare occasion an EMS horse needs them. Diet works best alongside weight control, exercise, and your veterinarian's guidance.
Low-Sugar Feeding Kit
Triple Crown Low Starch, Low Sugar Horse Feed
$62.99 on Amazon
Fortified low-NSC feed formulated for metabolic horses
Purina WellSolve Low Starch Feed
$62.49 on Amazon
Low-starch, low-sugar pellet diet for insulin-sensitive horses
Triple Crown Safe Starch Fortified Forage
$47.99 on Amazon
Grain-free, low-starch chopped forage for metabolic horses
Manna Pro Low-Sugar Apple Horse Treats
$13.76 on Amazon
No added sugar or molasses, safer treats for EMS horses
Start With Low-Sugar Forage
Forage is still the foundation of an EMS diet, it just has to be the right forage. Aim for hay tested at under roughly 10 to 12 percent NSC. The only way to know your hay's sugar is to test it, since color and softness tell you nothing reliable. Grass hays like timothy and orchard are usually safer than rich alfalfa or sugary varieties, but testing is what proves it. Feed forage at about 1.5 percent of body weight for a horse that needs to lose condition, and never let an EMS horse stand with an empty gut for long stretches.
If your only available hay tests a little high, soaking it for 30 to 60 minutes and discarding the water removes a useful share of the water-soluble sugar. It is an imperfect tool, but it can bring borderline hay into a safer range. Our guide to soaked feed for senior horses covers the technique.
Balance the Diet Without Grain
Forage alone is short on certain minerals, vitamin E, and quality protein, but you do not fix that with a bag of grain. For an EMS horse, the right tool is a low-calorie ration balancer or a vitamin and mineral supplement that supplies what forage lacks in a small, low-sugar serving. This keeps the diet complete without piling on the calories or starch that fuel the problem. Our roundups of the best ration balancers and best low-sugar feeds walk through suitable options.
If your horse truly needs a fortified feed rather than just a balancer, choose one specifically labeled low starch or low NSC and feed it at the rate on the bag. Standard senior and performance feeds are often far too high in sugar for a metabolic horse, so always read the tag.
Managing Grass and Pasture
Grass is the hardest part of EMS management, because pasture sugar swings wildly and can spike well above safe levels. Sugar is highest on sunny afternoons, after frost, and in stressed or drought-stricken grass. Many EMS horses do best with no pasture at all, living on a dry lot with measured low-sugar hay. If some turnout is possible, tools include:
- A grazing muzzle: Cuts intake sharply while still allowing movement and social turnout.
- Early-morning turnout: Grass sugar is usually lowest in the small hours and early morning, before the sun drives it up.
- A dry lot: The safest option for a high-risk horse, paired with hay in slow-feed nets to mimic grazing.
Slowing forage intake with a slow-feed hay net helps a muzzled or dry-lotted horse eat more like a grazing one, which is better for both the gut and the mind.
Weight Loss and Exercise
Many EMS horses are overweight, and shedding fat is one of the most powerful ways to improve insulin sensitivity. Aim for a Henneke body condition score around 5 out of 9, and reduce a heavy horse gradually with measured forage and more movement. Exercise, when the horse is sound, improves insulin response directly and helps burn off excess condition. Never crash-diet a horse, since rapid restriction carries its own risks. Our guide to weight management for senior horses covers safe, steady loss.
Adding Calories Safely (If Needed)
Most EMS horses need fewer calories, not more, but an older EMS horse that also has PPID and is losing weight may need safe energy added. The answer is never starch. Use highly digestible fiber like beet pulp and added fat such as oil or a rice bran product, which raise calories without spiking insulin. Introduce any change slowly and keep watching the feet. When EMS and Cushing's overlap, our Cushing's feeding guide covers the combined picture.
Watch the Feet Constantly
Because high insulin damages the hoof directly, laminitis is the ever-present danger with EMS. Learn the warning signs cold: heat in the hooves, a strong bounding digital pulse, reluctance to walk on hard ground, a rocked-back stance, or shifting weight from foot to foot. Any of these is a veterinary emergency. Catching laminitis early and pulling all sugar from the diet immediately can be the difference between a quick recovery and lasting damage.
The Bottom Line
Feeding an EMS horse means low-sugar forage first, balancing with a ration balancer instead of grain, and managing grass tightly with muzzles, dry lots, or early turnout. Keep the horse lean, keep it moving when sound, and add calories only through fat and fiber if a thin, older EMS horse ever needs them. Above all, watch the feet, since laminitis is what makes this condition dangerous. Test your hay, read every feed tag, and build the plan with your veterinarian, who can monitor insulin and adjust the diet over time.
EMS Feeding Quick Links
- Triple Crown Low Starch Feed - fortified low-NSC option
- Low-Sugar Apple Treats - no added sugar or molasses
- Browse low-starch horse feed on Amazon
Related Guides
- Feeding a Cushing's Horse - Low-NSC diet for PPID, which often overlaps with EMS.
- Best Low-Sugar Feeds for Horses - Low-NSC feeds compared.
- Weight Management for Senior Horses - Safe weight loss for easy keepers.
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Frequently Asked Questions
What is equine metabolic syndrome?
Equine metabolic syndrome, or EMS, is a cluster of issues centered on insulin dysregulation, where a horse's body produces too much insulin in response to sugar and starch. It often comes with regional fat deposits, such as a cresty neck, and a strong tendency toward laminitis. EMS is most common in easy-keeping breeds and ponies. It is managed mainly through diet, exercise, and weight control, and it frequently overlaps with PPID in older horses.
What should an EMS horse eat?
Build the diet around low-sugar forage, ideally hay tested at under about 10 to 12 percent non-structural carbohydrates, or soaked to lower its sugar. Avoid grain, sweet feed, and lush pasture. Balance the forage with a low-calorie ration balancer or a vitamin and mineral supplement rather than a fortified grain. If extra calories are ever needed, use fat and beet pulp instead of starch. Always confirm the plan with your vet.
Can an EMS horse have any grass?
Grazing is the single biggest sugar risk for an EMS horse, so most need restricted or no pasture, especially during high-sugar conditions like sunny spring days, frosty mornings, and stressed drought grass. Options include a grazing muzzle, a dry lot with soaked hay, or turnout only in the early morning hours when sugar is lowest. Your vet can help you decide how much grass, if any, your individual horse can safely handle.
Should I soak hay for an EMS horse?
Soaking hay for 30 to 60 minutes and pouring off the water leaches out a meaningful portion of the water-soluble sugars, which can bring borderline hay into a safer range. It is not a precise tool, since the amount removed varies, so the gold standard is still testing hay and choosing low-sugar forage. Soaking is a useful extra step, particularly when you cannot source ideal hay, but it works best alongside testing.
What is the link between EMS and laminitis?
High insulin directly damages the laminae that bond the hoof wall to the coffin bone, so an insulin-dysregulated horse can develop laminitis from a sugar spike without any other trigger. This is why sugar and starch control is the heart of EMS management. Any heat in the feet, a bounding digital pulse, shifting weight, or a sore, pottery walk is an emergency. Call your vet immediately and get the horse off all sugar.
How do EMS and Cushing's differ?
EMS is a metabolic and weight-driven condition seen across all ages, often in easy keepers, and it centers on insulin dysregulation. PPID, or Cushing's, is an age-related disorder of the pituitary gland that becomes common past the late teens and is treated with the medication pergolide. The two overlap often in older horses, and both raise laminitis risk, so the low-sugar diet is similar. Your vet can test ACTH and insulin to tell them apart.
Can EMS be reversed with diet?
Many EMS horses improve dramatically with weight loss, a low-sugar diet, and increased exercise, and some normalize their insulin response well enough to handle limited grass again. It is best thought of as managed rather than cured, since the underlying tendency remains. Consistent diet, body condition control, and regular veterinary monitoring keep most EMS horses sound and comfortable for years.
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