Laminitis AKA Founder: What is it?
Dr. Melyni Worth
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.