Laminitis is inflammation of laminae, the tiny, interlocking fingers that attach the coffin bone to the rest of the hoof. A complex sequence of events occurs during laminitis, resulting in inflammation of these laminae. When the inflammation is severe enough, the laminae die and the coffin bone is no longer supported in the hoof. If the bone rotates or sinks in the hoof, the horse is said to have “foundered”.The leading cause of laminitis is pasture (grass sugar) overload, but it can occur after any number of inflammatory conditions in the body, including:
Your veterinarian will perform a complete physical examination to determine the extent of the laminitis and discover what may have caused it. He or she may take x-rays initially as a baseline, and again a few weeks later to look for differences in the position of the coffin bone.
Generally, most horses with laminitis benefit from non-steroidal anti-inflammatory drugs (NSAIDs) like bute (phenylbutazone) for pain and swelling. If the laminitis is due to a gastrointestinal disturbance such as colic or diarrhea, Banamine® (flunixin meglumine) may be given to fight endotoxins. Antibiotics will be administered if infection is present. Sometimes medications that dilate blood vessels, such as acepromazine or isoxsuprine, are given to help encourage better circulation in the foot. Horses that develop laminitis due to Cushing’s Disease should receive daily Prascend® and/or cyproheptadine to manage the underlying condition. Thyro-L® (levothyroxine) is being investigated as a treatment for the Insulin Resistance seen in Equine Metabolic Syndrome and may be a useful prescription drug for prevention of laminitis.
It is very important to provide mechanical support to the hoof during a bout of laminitis, and your veterinarian and farrier should work together to accomplish this. At first, stall rest may be recommended. Later, as the horse becomes more comfortable, short periods of hand walking may help increase circulation to the damaged hoof tissue.
Depending on the cause of the laminitis, your horse may be put on a restricted diet. If caused by pasture or grain overload, or if Cushing’s Disease or Equine Metabolic Syndrome are suspected, then grass, grain, treats and other foods high in sugar may be off limits. A vitamin/mineral supplement may be necessary to meet minimum nutrient requirements for horses on restricted diets.