Laminitis is an inflammatory condition of the sensitive laminae — the interdigitating tissue layers that bond the coffin bone to the inner hoof wall inside the hoof capsule. When blood flow to the laminae is disrupted or overwhelmed, the tissue becomes ischemic, inflamed, and structurally weakened. In severe cases the coffin bone loses its lamellar attachment and rotates or sinks within the hoof capsule, a condition called founder. Laminitis is one of the most serious and potentially career-ending conditions in horses and is a leading cause of equine euthanasia when severe rotation occurs.
The condition most commonly affects the forefeet, which bear approximately 60 percent of the horse’s body weight, though all four feet can be involved. Acute episodes present as intense pain in the feet — the horse adopts a characteristic “sawhorse” stance, shifting weight back onto the hindlimbs to relieve pressure on inflamed forefeet, and is reluctant to move or turn. The digital pulse at the pastern and fetlock region is often bounding and elevated. The frog may feel warm compared to surrounding structures. Diagnosis is confirmed by clinical signs, hoof tester response, and radiographs showing the degree of coffin bone displacement relative to the hoof wall.
Triggers include excessive carbohydrate intake from lush pasture or grain overload, systemic illness such as colitis or retained placenta, Equine Metabolic Syndrome, Pituitary Pars Intermedia Dysfunction (PPID), prolonged weight-bearing on a contralateral limb due to an existing soundness problem, and administration of certain corticosteroids. Management in the acute phase centers on removing the inciting cause, strict box rest on deep soft bedding, cold therapy applied to the feet, and non-steroidal anti-inflammatory medication. Long-term management involves a skilled therapeutic farrier to realign the coffin bone and redistribute load, dietary restriction of soluble carbohydrates, and regular radiographic monitoring. Horses on pasture prone to laminitis should have body condition assessed regularly, as obesity is a major predisposing factor.
Further Reading
- laminitis (Wikipedia)
- For pathophysiology, grading, and treatment of equine laminitis: laminitis in horses — Merck Veterinary Manual