Laminitis is a painful condition in horses where the soft tissue connecting the hoof wall to the bone inside the hoof becomes inflamed and begins to weaken or fail. It can range from mild lameness to a life-threatening emergency, and it is one of the most common causes of chronic pain and euthanasia in horses. Understanding what triggers it and how to recognize it early can make the difference between a full recovery and permanent damage.
What Happens Inside the Hoof
A horse’s entire body weight is suspended from the inside of the hoof wall by thousands of tiny, interlocking tissue layers called laminae. Think of these like Velcro: one side is attached to the bone inside the hoof (the coffin bone or pedal bone), and the other side is attached to the inner surface of the hard hoof wall. This connection is what keeps the bone in place and allows the horse to bear weight on its feet without the skeleton simply pushing through the bottom of the hoof.
In laminitis, something triggers injury to these laminae, weakening the bond between bone and hoof wall. In mild cases, the tissue becomes inflamed and painful but stays intact. In severe cases, the laminae can actually separate, allowing the coffin bone to shift downward or rotate inside the hoof capsule. When the bone displaces, the condition is called “founder,” and it can cause permanent structural damage. The bone can even penetrate through the sole of the hoof in the worst scenarios.
Three Main Causes
Laminitis isn’t a single disease. It’s a clinical syndrome that develops through three distinct pathways, and knowing which one is involved shapes how it’s treated.
Endocrine (Metabolic) Disease
This is by far the most common cause. In one study of horses presented for laminitis at a university veterinary hospital, 89% had an underlying hormonal disorder. The two main culprits are Equine Metabolic Syndrome (EMS) and Pituitary Pars Intermedia Dysfunction (PPID, sometimes called equine Cushing’s disease). Both conditions lead to abnormally high insulin levels in the blood, and that excess insulin directly damages the laminae.
Of the horses with a hormonal disorder in that study, about two-thirds had insulin resistance consistent with EMS, while one-third had PPID. EMS tends to affect younger, overweight horses and ponies, especially those that are “easy keepers” prone to gaining weight on minimal feed. PPID is more common in older horses and often shows up as a long, curly coat that doesn’t shed normally. Either condition can smolder undetected for months or years before a laminitis episode forces the diagnosis.
Systemic Inflammation or Infection
Severe illness can trigger laminitis even in horses with no metabolic problems. Conditions like grain overload (when a horse breaks into the feed room), retained placenta after foaling, or serious colic with gut compromise can cause a body-wide inflammatory response. Toxins released into the bloodstream damage the blood supply to the laminae, and laminitis can develop within 24 to 72 hours of the original illness. This form tends to come on fast and can be severe.
Support-Limb Overload
When a horse has a serious injury in one leg, it shifts its weight onto the opposite limb for extended periods. The constant mechanical stress overwhelms the laminae in the weight-bearing foot. This is the type of laminitis that famously affected the racehorse Barbaro. It’s less common than metabolic laminitis but can be devastating because the horse is already dealing with a primary injury.
Signs and Severity
The hallmark of laminitis is pain in the feet. In most cases, the front hooves are affected more severely than the hinds, because horses carry about 60% of their body weight on their front legs. The classic posture is a horse leaning backward, stretching its front legs out to shift weight onto the heels and away from the painful toe area.
Veterinarians grade laminitis severity on a four-point scale. At the mildest level, a horse shifts weight between its feet at rest and moves with a short, stiff gait at the trot but walks relatively normally. At grade two, the stiffness is visible even at the walk, the horse resists trotting on hard ground, and turning becomes difficult. Grade three horses are reluctant to walk on any surface and may be nearly non-weight-bearing on one limb. At the most severe grade, the horse refuses to move without being forced, resists transitioning from soft to hard ground, and won’t allow any foot to be lifted.
Other signs include increased heat in the hoof wall, a strong or “bounding” digital pulse felt at the back of the pastern, and sensitivity when pressure is applied to the sole. Some horses will lie down more than usual simply to get weight off their feet.
How Laminitis Is Diagnosed
A veterinarian can often suspect laminitis based on the characteristic gait and posture alone, but X-rays of the feet are essential for assessing how much damage has occurred. Radiographs show whether the coffin bone has rotated or sunk within the hoof capsule, and they provide a baseline for tracking changes over time. Blood tests to measure insulin levels and screen for PPID are a standard part of the workup, since identifying a metabolic cause changes the long-term management plan.
Immediate Treatment
The first priority is pain control and limiting further damage to the laminae. Horses in an acute episode are typically given anti-inflammatory medications and moved to deep, soft bedding that cushions the sole and distributes weight more evenly across the foot.
One of the most effective interventions during the early stages is continuous cooling of the lower legs and hooves. Keeping hoof temperature below 10°C (50°F) slows the inflammatory process and protects the laminae from further breakdown. This is usually done with ice boots or by standing the horse in an ice-water slurry. The key word is “continuous”: intermittent icing is far less effective. In horses at risk from a systemic illness (like colic or grain overload), starting cryotherapy before laminitis develops can prevent it altogether.
If a metabolic disorder is identified, treatment of the underlying condition begins immediately. For PPID, this means medication to normalize hormone levels. For EMS, the focus is on dietary restriction and a gradual weight-loss plan.
Diet and Long-Term Management
For horses with metabolic laminitis, diet is the single most important long-term intervention. The goal is to limit sugars and starches, collectively called non-structural carbohydrates (NSC). High-risk horses should eat a diet containing less than 10% NSC on a dry matter basis. Moderate-risk horses can tolerate up to 15 to 20%.
In practical terms, this means eliminating grain-based feeds, sweet feeds, and treats high in sugar. Hay should be tested for its NSC content, since it varies widely depending on the type of grass, when it was cut, and growing conditions. Soaking hay in cold water for 30 to 60 minutes can leach out a portion of the soluble sugars, which is a useful strategy when hay testing isn’t available or when the NSC is borderline.
Pasture access is one of the biggest risk factors. Grass produces more sugar during cool, sunny weather and during periods of rapid growth in spring and fall. Many laminitis-prone horses need to be kept off pasture entirely, or their grazing time needs to be strictly limited using a dry lot or grazing muzzle. This can feel restrictive, but for a horse with EMS or PPID, unrestricted grazing on lush pasture is one of the most reliable ways to trigger a new episode.
Hoof Care and Therapeutic Shoeing
The mechanical support provided to the hoof during and after laminitis is critical for recovery. In the acute phase, foam pads, styrofoam blocks, or commercial frog-support boots can be taped to the foot to provide immediate relief by transferring weight from the damaged hoof wall to the frog and sole.
Once the acute crisis stabilizes, a farrier experienced in laminitis cases works to realign the hoof capsule and reduce stress on the damaged laminae. The standard approach involves trimming the heels back to the widest part of the frog and correcting any distortion in the hoof shape. Therapeutic shoes typically include a raised heel (usually 1 to 2 degrees of wedge) and a rolled or “rockered” toe that makes it easier for the horse to break over at each step. This combination reduces the pull of the deep digital flexor tendon on the coffin bone, which is one of the forces driving bone rotation.
Some horses do well transitioning back to barefoot trimming once the laminae have healed and the hoof has grown out. The barefoot approach focuses on keeping heels low and rolling the toe forward from the front of the coronary band. Others need ongoing mechanical support with shoes or boots for the rest of their working lives. The right approach depends on the severity of the original episode, the degree of bone displacement, and how the hoof grows out over the following months.
Recovery Timeline and Prognosis
Mild laminitis caught early, especially when the coffin bone hasn’t moved, carries a good prognosis. Many horses return to comfortable soundness within weeks to a few months, though they remain at higher risk for future episodes if the underlying cause isn’t managed. The hoof wall grows from the coronary band downward at roughly 6 to 10 millimeters per month, so a full hoof capsule takes 8 to 12 months to replace itself. During that time, the new growth reflects the health of the laminae going forward.
Severe laminitis with significant bone displacement is a different situation. These horses may require months of stall rest, repeated radiographs, and multiple rounds of corrective trimming or shoeing. Some recover enough to be pasture-sound or return to light work. Others, particularly those where the coffin bone has penetrated the sole or where chronic pain can’t be controlled, face a guarded to poor prognosis.
The single biggest factor in long-term outcome is owner commitment to managing the underlying cause. A horse with well-controlled EMS or PPID, a carefully managed diet, and regular farrier care can live comfortably for many years after a laminitis episode. Without those changes, recurrence is nearly inevitable.