Horse Founder (Laminitis)

Horse Founder, technically known as Laminitis, is a condition of the foot that is almost always caused by the horse’s diet. Grain overload or overeating lush pasturage are the most common causes, but it can also be the result of trauma, systemic infection from the retained placenta, ingestion of cold water, and apparently from some anti-inflammatory drug treatments.

When a horse suffers from founder, he’ll usually walk very gingerly, as each step is terribly painful. It usually appears in the front feet, but occasionally the hind feet are affected as well. More often than not, the condition appears in overweight horses and ponies that are kept in lush pasture.

Initially, the horse will be extremely reluctant to move. The animal will often be found standing with its hind legs well under the body in order to lighten the load on the front feet. Additionally, he may roll back on his front heels to take the weight off the toes. The area above the hoof wall and the coronary band will be hot to the touch, and you’ll be able to feel a powerful, thumping pulse.

The horse’s foot is composed of two laminae, or leaves of tissue: The sensitive lamina, which contains nerves and blood vessels, and the insensitive lamina, which lines the horny hoof wall (Check your anatomy chart for details; we have detailed horse anatomy and hoof anatomy charts available through our Library.
Horse founder, or Laminitis is a condition of the sensitive lamina. The tissue breaks down and becomes inflamed as a result of a reduction in blood flow. Swelling occurs and pressure from the swelling in the close confinement of the hoof wall results in more acute pain. If left untreated, this can result in rotation of the distal phalanx (coffin) bone in the hoof and even its penetration through the sole of the foot. This is as frightful as it sounds.

In chronic cases, as the coffin bone rotates due to tissue breakdown and upward pull of the deep digital flexor tendon, lamina may separate at the horse’s toe, resulting in what’s called “seedy toe”. There may be a secondary infection here if bacteria are allowed to colonize the void.

If you suspect Laminitis, your first move is to call your Veterinarian. He can examine the foot to confirm your suspicions; an x-ray will provide the final assurance. While you’re waiting for him, eliminate any obvious cause. If your horse or pony is overweight and grazing on lush pasture, get her into a stall or location where there is no grass. If she’s been in the grain, her stomach should be flushed to remove as much as possible, and if your mare has foaled and retained the placenta, she should be treated appropriately.

Your vet may recommend treatment of the Equine founder itself with antibiotics and anti-inflammatory drugs. Some may also prescribe Heparin to prevent clots; Phenoxybenzamine to prevent constriction of the blood supply and Acepromazine to keep the blood vessels dilated.

Cutting the DDF Tendon is a dramatic tactic used only in critical cases of chronic laminitis, where rotation of the coffin bone is out of control. And in some extreme case where other therapies do not help, removal of the entire hoof wall from the coronary band to the ground around the front half of the hoof may provide some relief. Remember, though, that re-growth will take up to a year, and the foot must be kept scrupulously clean and bandaged until firm protective tissue re-develops.

There are other steps you can take to complement the Vet’s recommendations. Keep the horse in soft sand or other deep bedding to give complete support to the sole. Eliminate grain from the diet entirely. Treat the hoof with Low Energy Photo Therapy (LEPT). LEPT, also known as Light Therapy, consists of applying clusters of red and infra-red light-emitting diodes pulsed at specific frequencies to the affected area. This therapy will increase blood flow and reduce swelling. It will also stimulate the production of nitrous oxide (NO) and accelerate the healing process.
Acupuncture and acupressure are also helpful in treating the pain associated with laminitis.
If x-rays confirm that the coffin bone has rotated, once the acute phase of the condition has passed careful trimming will help to re-align the bone to the hoof. This will, of course, require cooperation between your veterinarian and farrier, as repeated x-rays will be required to gauge progress.

The long-term prognosis for horse founder is always sketchy. If the problem is caught quickly, and rotation of the coffin bone does not occur, your equine friend should regain his former level of performance. The general rule of thumb is: if the rotation is less than 5º, then full recovery is almost assured; greater than 10º and full recovery is unlikely.

If caught quickly, your horse should generally show improvement within twenty-four to thirty-six hours after treatment begins. However, treatment will need to be continued for a considerable amount of time before healing is complete.

Please bear in mind that any horse that has once had an episode of founder is pre-disposed to recurrences. Maintain conditions that will minimize that possibility: Carefully manage your horse’s weight, pasturage and farriery so you can give him the best chance of avoiding a future attack of this painful and dangerous condition.

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