Laminitis in Horses & Hoof HealthBy: Dr. Lydia Gray
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:
- Grain (sugar) overload
- Colic or diarrhea
- Uterine infection or retained placenta
- Equine Metabolic Syndrome (Insulin Resistance) or Cushing’s Disease
- Excess weight-bearing on a limb
- Infections in the blood, lungs or other organs
- Shifting weight from foot to foot
- Painful-looking gait (described as “walking on eggshells”)
- Classic founder stance (leaning back so hind feet bear more weight)
- Warm feet, bounding digital pulses
- Sweating, increased heart and respiratory rates
- Reluctance to move or get up from lying down
Omega-3 fatty acids because of their anti-inflammatory properties. Antioxidants such as Vitamin E are also appropriate. Horses that develop laminitis due to Equine Metabolic Syndrome may benefit from supplements that contain Chromium and Magnesium, which have been shown to support proper insulin and sugar metabolism. Because healthy hoof re-growth is important, supplements that contain Biotin, Methionine and Zinc may be recommended.
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.
- Why did my horse develop laminitis?
- Is he now more likely to develop it again?
- Will I be able to ride him again?
Further Reading for You:
From the SmartPak Ask the Vet Blog:
From The Horse Journal:
- Chronic Laminitis Requires a Lifestyle Change, May 2004
- Emergency: Acute Laminitis Attack, April 2004
- Feeding a Founder Attack, April 2004
- Head into the Horror of Laminitis Well-Armed, February 2002
- No Sweets for Laminitis-Prone Horses, June 2002
- New Theory for Grass-Induced Laminitis, July 2002
- Step off the Laminitis Bandwagon, March 2008
Further Reading for Your Veterinarian
Neelley KA and Herthel DJ. Essential fatty acid supplementation as a preventative for carbohydrate overload-induced laminitis. In: Proceedings of the 43rd Annual AAEP Convention;pp367-369.
Treiber KH, Kronfeld DS, Geor RJ. Insulin resistance in equids: possible role in laminitis. J Nutr. 2006 Jul;136(7 Suppl):2094S-2098S.
Van Eps AW, Pollitt CC. Equine laminitis: cryotherapy reduces the severity of the acute lesion. Equine Vet J. 2004 Apr;36(3):255-260.
About Dr. Lydia Gray