Laminitis AKA Founder is a condition where the sensitive laminae of the feet become inflamed and swell causing separation of the tissues. As the laminae 'glue' the pedal bone to the front wall of the hoof and are the main support mechanism of the foot, this separation causes a lot of mechanical problem, including the commonly seen 'sinking' or rotation of the pedal bone down through the sole. The condition is very painful, and can come on VERY suddenly. Unfortunately for us it has a lot of different causes.

Causes:

Presence of bacterial toxins, which cause a loss of blood supply to the foot. The resident bacteria in the hind gut can produce these toxins because there is some kind of interference with their normal activity. They can come from an over abundance of the 'wrong' bacteria in the GI tract due to various factors. These undesirable bacteria can grow in the hind gut because too much simple carbohydrate escapes the small intestine, (this is what follows when the horse gets into the feed room, and over eats grain). These toxins can also be as a result of bacteria dying in the GI tract due to colic or over heating. Another source can be from bacteria growing in the uterus due to retained placenta, or from any kind of massive bacterial over growth for whatever reason.

Interference in peripheral circulation causing a reduction of blood supply to the hoof capsule and hence a shortage of oxygen and or nutrients to the laminae. The interference of blood supply can be due to insulin resistance (type 2 diabetes), shock from exhaustion, or stress causing shut down of peripheral circulation, amongst other things.

Over dose of cortico-steroids, both endogenous (self producing) such as in Cushings disease or stressed horses, and exogenous (overdosing steroids by the vet or others!). One effect of cortico-steroids on the system is to reduce peripheral circulation and the horse is particularly sensitive to this.

Toxins present in the environment that get into the foot such as when the horse stands on black walnut or other hard wood shavings.

There is some current research that shows that Nitric Oxide is a direct messenger for many functions including control of vasodilation (opening of arteries), It is interference or loss of NO that shuts down the circulation to the laminae. So anything that increases NO in the lower leg/foot will help. This can include feeding the appropriate amino acids, nitro-glycerin plasters onto the coronary band, and using a therapy laser onto the coronary band/foot, pulsating magnetic fields onto the foot capsule. All of these separately or together can and will reduce the pain and discomfort, halt the death of the laminae and stop the sinking or rotation of the pedal bone if gotten on fast enough.

A horse with an injury to a limb such that it cannot or will not bear weight on it, can cause the opposite limb to founder due to stress and strain.

Feeding the Foundered Horse

Feeding wise, most founders NOT due to toxemia or exhaustion or carrying all the weight on one foot, are the resistance to insulin kind. Feed the horse as a diabetic, give feeds with low glycemic index. Use a feed high in amino acids, high Magnesium (Magnesium is used in human diabetics to enhance peripheral circulation), essential fatty acids, minerals etc. Feeding a foundered horse usually means a magnesium/chromium supplement, with or without an amino-acid supplement, and an essential (as in Omega 3) fatty acid supplement. Feed grass hay, possibly a little alfalfa hay, or rinsed sugar beet. BUT stay away from corn, oats, barley especially stay away from sugar as molasses. Feed extra fat in the form of oil or rice bran if you need to get energy into the horse.

The pre-Cushinoid horse (usually insulin resistant) will also benefit from a supplement high in magnesium and chromium.

Post founder, feed a feed that will support hoof growth without excess carbohydrates. This means the best possible blend of amino acids and essential fatty acids, with a good supply of digestible minerals and vitamins.

Preventing Founder

• Preventing founder is done best by constant vigilance over the quality of the feed, and the body score of the horse.
• Over weight horses are more prone, so keep their weight down. If they are over weight feed a magnesium/chromium supplement and reduce or eliminate their grain so that they lose weight.
• Don't over feed carbohydrates (grain).
• Check the placenta on all foaling mares, to make sure it is intact. If a bit is missing, call the vet!
• Keep the feed room securely shut to prevent unauthorized invasions.
• Don't overdose steroids.
• In spring, keep susceptible horses off the fresh grass by limiting their grazing time.
• Prevent or treat rapidly over heating from exercise or fever.
• Avoid hardwood shavings in the bedding.
• If the horse has an injury to one limb such that it bears no weight on it, support the other limb(s) with wraps or boots so that they get some help.