Laminitis ranks second only to colic in surveys of horse owner’s greatest fears. When severe enough to result in founder, or deformity of the foot, it is the most devastating of horse diseases and has the worst prognosis. Laminitis can strike all horses regardless of breed or use, but is rarely found in horses less than one year of age. However, it is most commonly seen in obese horses, those who suddenly overeat on corn or other starches (starch overload founder), after colic or other debilitating conditions and in horses grazing in certain situations (grass founder). The best strategy is to prevent laminitis and founder. They are every horse and horse owners’ nightmare.

Laminae, the sensitive tissues that connect the hoof wall to the coffin bone and other structures in the foot, act like tiny velcro strips. Laminitis, or inflammation of the laminae, can lead to a loss of integrity of the bond holding the hoof wall to the coffin bone. Inflammation also leads to ischemia (cell death) due to loss of blood supply, therefore loss of nutrients and oxygen in the cells. If the laminae pull apart, the tip of the coffin bone rotates downward and the wall moves out forward giving the classic look of the foundered foot. The horse is ‘foundered’ when there is visible deformity of the foot and radiographs show a separation of coffin bone from wall.

The onset of laminitis is always an emergency. Symptoms usually occur in one or both front legs, but can occur in all four legs. Symptoms include bounding digital pulse in the arteries just above the hooves, rocking back to put more weight on the hind legs and being reluctant to or refusing to move. In severe cases the horse usually lies down and is reluctant to rise. If your horse has laminitis symptoms, contact your veterinarian immediately and keep the affected limbs as cool as possible until he/she arrives. To accomplish this, hose the legs and feet with cold water, stand the horse in a cold stream, wrap the feet and lower legs in sacks with ice or stand the horse in tubs of ice water. The cold temperature will deactivate the enzymes responsible for pressure-associated separation of the laminae until the horse can be treated. Once separated, the laminae cannot be reunited and the hoof takes over a year to re-grow from the coronary band to the ground.

Prevention
Laminitis associated with obesity is relatively easy to prevent. “The fat ones get less and the thin ones get more” (calories not pounds of feed). Horses must be maintained at a condition score of 5-6 on a scale of 1-9 to lessen the risk of founder due to obesity. See the Body Condition Scoring section for help determining a horse’s current body condition. There is a tendency for some owners to overfeed horses, not realizing the dangers involved.

Starch-overload founder can be avoided by feeding low-starch feeds like GROSTRONG® Ultra-Fiber®, SENIORGLO® and Patriot® Performance Horse Feeds. It is also important to store feeds safely, so that horses cannot help themselves and over eat, and to feed according to label instructions. It is especially important to safely store all whole corn and feed made for other species of animals out of the reach of horses.

Grass founder is the result of grazing grasses with high fructan content. Fructan is a starch-like compound that cannot be digested in the foregut by enzymes. It therefore enters the cecum where it is rapidly fermented, similar to corn starch, often resulting in starch-overload founder. The fructan content of grasses varies according to the type of grass, stress on the plants, fertilization and hydration of the plants, climate, and even time of day. If a horse has foundered in a specific pasture setting, fructan content should be considered, and horses removed from that location.

Other causes of founder include; pneumonia; pleuritis; severe colic; Potomic horse fever; colitis caused by Salmonella sp. bacteria, stress resulting from constant movement, shipping, showing, loss of sleep, water deprivation, or dehydration; unilateral lameness brought about when a horse suffers a severe injury in one leg or foot and places excess weight on the opposite limb; road founder (excessive concussion for a long period of time); accidents or mechanical trauma; black-walnut shavings used as bedding; retained placenta for more than 12 hours (resulting in infection), mastitis in lactating mares, enteritis/colitis and complications following surgery.

Recovery
Horses with laminitis need specific amino acids, fatty acids, vitamins and minerals to re-grow damaged hoof tissues. They should not be starved as therapy. Remove all grains and starchy feeds immediately. Then make changes in feeds slowly. Minimize stress to the hindgut by feeding highly digestible fibers, vegetable oils as needed, and balanced protein, vitamins and minerals.

GROSTRONG Mintrate® is an excellent top-dress for hoof growth. Consider probiotics for the first 30-60 days after an acute episode. Restrict grazing if grass fructan concentration is a concern. For weight loss, reduce hay and mix with clean wheat or oat straw. Keep the horse on bare paddocks, use a muzzle for some of the time, use electric fencing to restrict grazing, feed little and often, do not overfeed, and consider fructan concentrations of grasses when turning out. If the horse is able to work, then feed him in multiple, small meals. Always increase the work load before increasing the feed.

Founder often ends the career or life of a horse. It is absolutely essential to do everything you can do to prevent it.

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