Feeding the laminitis-prone horse

For a metabolic horse, sugar in the diet isn't a comfort — it's a trigger. Feeding to keep the feet attached means controlling carbohydrates with a discipline most barns find uncomfortable.

Once a horse has had laminitis, or carries the metabolic markers that predict it, the feed program stops being about condition and shine and becomes about keeping the coffin bone where it belongs. We think of these horses the way a physician thinks of a diabetic patient: the diet is medicine, and a single careless spring afternoon on rich grass can undo months of careful work. The good news is that the science here is clear, even when the management is inconvenient.

Most laminitis we see now is endocrinopathic — driven by insulin dysregulation from equine metabolic syndrome (EMS), PPID (Cushing's), or both. High blood insulin damages the laminae that suspend the coffin bone inside the hoof wall. Anything that spikes insulin is the enemy, and the biggest dietary driver of that spike is non-structural carbohydrate (NSC): the sugars, starches, and fructans in feed and forage. The single number that matters most for these horses is the NSC of the total diet, and the target is to keep it under about 10 to 12 percent. To get the full clinical picture of the disease itself, pair this with understanding laminitis and founder.

Forage is where the war is won or lost. Test your hay — for a laminitic horse this isn't optional, it's the only way to know your NSC. Choose a mature grass hay (never a rich, leafy early cutting, and rarely straight alfalfa for the insulin-resistant), and if the tested NSC is too high, soak it. Soaking hay in cold water for 30 to 60 minutes leaches out a meaningful portion of the water-soluble sugars; soak for the shorter time in warm water or longer in cold, then dump the sugary soak water well away from the horse. Feed it in a small-hole net so the lower-calorie ration still lasts most of the day, because long empty stretches cause their own problems.

Grass is the classic trigger, and it deserves real fear. Pasture sugar swings wildly — it's highest on sunny afternoons, after a frost, and during the spring and fall flushes, and a metabolic horse turned out on lush grass can be foundering within days. Many of these horses need a dry lot with tested hay rather than pasture, full stop. If they do graze, it's muzzled, in the early morning, and never during high-risk windows. This overlaps heavily with general weight control, since most laminitis-prone horses are also easy keepers, and the muzzle-and-drylot toolkit is the same one we lay out in managing the easy keeper's weight.

The feed bucket must be ruthlessly low-sugar. No sweet feed, no molasses, no oats, no treats with grain or apples and carrots in any quantity — yes, carrots are sugar. What these horses do need is balanced vitamins, minerals, and quality protein without calories or starch, which is exactly what a low-NSC ration balancer provides in a one-to-two-pound serving. If a horse genuinely needs more calories (uncommon, since most are too fat), add them from fat and super-fibers like soaked beet pulp rather than grain. Magnesium and chromium supplements are sometimes used to support insulin sensitivity, but they're an adjunct to diet, not a substitute, and worth discussing with your vet.

Weight and movement are part of the prescription. Obesity worsens insulin dysregulation, so a fat laminitic horse needs to lose weight — carefully, never below 1.5 percent of ideal body weight in forage. Exercise improves insulin sensitivity directly and is hugely protective, but only once the feet are stable and your vet clears it; working a horse through an active laminitic episode does real damage. During an acute flare, the rules tighten further: soaked low-NSC hay only, stall rest on deep bedding, and the vet directing every decision.

This is a team effort with your veterinarian, not a solo feed-room project. Horses with EMS or PPID should be tested — insulin, glucose, ACTH for Cushing's — and PPID horses managed with pergolide alongside the diet. Re-test, re-weigh, and adjust seasonally, because risk climbs every spring and fall. It's a demanding way to feed a horse, and owners chafe at the muzzles and the soaked hay and the banned carrots. But we've watched the discipline pay off: the pony who foundered three springs running, once moved to a dry lot with tested, soaked hay and a ration balancer, went years without another episode. For these horses, boring is the goal, and a controlled, low-sugar, forage-based diet is what boring looks like.