By the time a horse shows signs of laminitis, damage to the coffin bone’s supporting tissues, called the lamellae, has often already begun. Identifying and managing insulin dysregulation (ID) before clinical signs of laminitis appear offers one of the best opportunities to prevent this painful condition, said Andrew van Eps, BVSc, PhD, Dipl. ACVIM, professor at the University of Pennsylvania’s New Bolton Center, in Kennett Square, during his presentation at the 2026 American College of Veterinary Internal Medicine Forum, held June 11-13, in Seattle, Washington.

Hyperinsulinemia, or persistently high blood insulin concentrations, is the primary driver of endocrinopathic laminitis in horses. While obesity, pituitary pars intermedia dysfunction (PPID), age, stress, pregnancy, certain medications, and high nonstructural carbohydrate (NSC) intake can all contribute, the elevated insulin itself causes damage to the lamellae, said van Eps.

Identifying Insulin Dysregulation in Horses

Horse owners should work closely with their veterinarians to identify ID before lamellar damage occurs. Van Eps recommended annual metabolic screening for most horses younger than 10 years old, except for those in intense aerobic work such as racehorses, endurance horses, and upper-level eventers (who are less likely to be at risk of metabolic disease). He said horses older than 10, as well as breeds or individuals considered at higher risk (i.e., pony breeds, Warmbloods, and gaited horses), should be screened twice yearly—in the spring and fall. Veterinarians should also include PPID screening as a part of routine testing in senior horses.

While insulin remains the cornerstone of equine metabolic screening, newer biomarkers can help identify horses at risk even earlier. “Adiponectin (a hormone that improves insulin sensitivity) is an independent predictor of laminitis risk,” said van Eps. “Horses with normal insulin but low adiponectin may still have an increased likelihood of developing hyperinsulinemia after a feed or sugar challenge and warrant close monitoring and additional testing.”

Managing Horses at Risk for Laminitis

Managing horses at risk focuses on reducing insulin spikes before they damage the lamellae. Horses with ID benefit from diets low in nonstructural carbohydrates (NSCs). In overweight horses and ponies Van Eps recommended restricting forage intake for weight loss when appropriate and feeding hay that either tests below 10% NSC or has been soaked before feeding.

Generally, the safest time for these horses to graze is late at night or early in the morning, before the sun comes up. Avoid afternoon and early evening grazing, lush spring or fall grass, and pasture stressed by frost or drought because these conditions can increase NSC concentrations in grass.

When management changes haven’t controlled a horse’s ID, van Eps said veterinarians might consider medication alongside dietary modifications:

• SGLT2 inhibitors (ertugliflozin, canagliflozin, and bexagliflozin) effectively reduce hyperinsulinemia and can help prevent laminitis in high-risk horses. However, the horse’s insulin concentrations typically rise again after treatment ends unless diet, exercise, and weight management improve insulin sensitivity.
• Pioglitazone increases adiponectin concentrations and can improve insulin sensitivity. Van Eps said it can be useful for horses with mild ID and low adiponectin or in combination with an SGLT2 inhibitor.
• Metformin has inconsistent effects and veterinarians no longer consider it a first-choice treatment for ID in horses.
• Levothyroxine can help horses lose weight when used alongside feed restriction, but veterinarians should only prescribe it as a short-term therapy.

Take-Home Message

Preventing laminitis involves identifying equine metabolic abnormalities early and managing a horse’s insulin levels before lamellar damage occurs inside the hoof. Work with your veterinarian to develop a feed, exercise, and in some cases a medication routine to meet your horse’s needs.