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Acute laminitis

23 May, 2013
Topic: Hoof and Foot Lameness
Answer Provided by: Mike Pownall DVM

Question:

What causes acute laminitis?

Answer:

The sudden onset of laminitis in an otherwise healthy horse is always a mystery. It appears that your veterinarian is doing a great job but you pose a question that many people may want to know the answer to. Contrary to popular assumptions, a horse can develop acute laminitis without any other prior signs. One moment they are healthy and two hours later they can barely walk.

Laminitis is the inflammation of the laminae that attach the coffin bone to the hoof. Think of the attachments as similar to velcro. Inflammation causes the attachments to weaken, allowing them to be separated easily. The deep digital flexor tendon is attached to the bottom of the coffin bone in the heel area, and a healthy foot maintains an equilibrium between the bonds holding the bone to the hoof and the pull of the DDF tendon. When the bonds weaken, the pull of the tendon causes the bone to separate away from the hoof and rotate downward. This is similar to when a team is winning a tug of war match. A little lead suddenly cascades into the losing team being pulled over easily. The body under certain conditions will release chemicals that weaken the lamellar bonds, leading to laminitis. Both carbohydrate overload and septicemia can allow the large intestine of the colon to leak these damaging substances. Horses that suffer from metabolic diseases such as cushing’s syndrome and insulin resistance are also prone to laminitis, due to disruption of glucose uptake by the laminae. Excessive repetitive trauma can also lead to inflammation and deterioration of the laminae (often called road founder ot mechanical founder).

Once your horse has laminitis it is necessary for your farrier and veterinarian to work closely together because your horse will need the expertise of both.

Mike Pownall DVM