PROPER
HOOFCARE, OR:
WHAT YOU NEED TO KNOW ABOUT YOUR HORSE'S FEET
A horse, in its natural environment,
travels an average of 15-30 km (10-20 miles) per day with its herd,
over various terrain. The hooves adjust to the type of terrain (whether
desert sand, prairie sod, the shaly, rocky ground of Iceland, or the
wetlands of the Camargue): horn growth and wear are in balance, and
the functionally optimal conformation and shape of the hoof is naturally
maintained. The hoof remains supple and elastic through daily contact
with mud or water as the horse drinks. It does not have, nor need, any
type of grease or oil or artificial moistening agents.
Under the care of humans,
however, horses almost always fall short of their natural (and biologically
required!) amount of movement. As a result of this, in order to imitate
the natural amount of wear on the hoof, it is necessary to trim it--far
more often than every 6-8 weeks.
For hoofcare specialists
and horse owners working according to Dr. Strasser's methods, trimming
in two week intervals is normal, if they are not riding enough. This
makes it possible to keep the sound hoof in its physiologically ideal
shape (by, for example, preventing the bars from growing too long, and
the heels from growing beyond the level of the frog and bulb of the
heels, thus doing damage to the interior of the hoof, especially the
navicular region). It also allows the healing of deformed hooves and
other hoof-related ailments (contracted heel, laminitis, navicular syndrome,
thrush, arthritis, to name a few). However, a certain amount of knowledge
about the function of the hoof and its physiologically proper shape
is necessary for this endeavor.
There are several prerequisites
for a functionally sound hoof.
1. Generally, the front hooves
have an angle of about 45 degrees and are round in the toe area, while
the hind hooves are somewhat steeper, around 55 degrees, and more pointed
in the toe region. This way, the front feet are able to carry the main
part of the horse's weight and function as excellent shock absorbers,
and the hind feet provide the spring and elasticity for propulsion (and
the tip can dig into the ground).
2. A large part of the frog
has ground contact, to allow for a feel of the ground, carry weight,
and function as shock absorber. It is widest in the area of the heels;
if you drew a line along the edge of the frog from tip to heel, the
extension of this line should pass on the outside of the bulb of the
heel. If it intersects with the bulb of the heel, the hoof is contracted
(usually as a result of shoeing and/or improper trimming).
3. The hoof wall and especially
the heels are barely above the level of the sole, and the heels not
above the level of the frog, since otherwise damaging lever forces in
the hoof can arise.
4. The sole is smooth and
slightly concave; only in the area of the front toe does it help carry
weight (about 1 cm or 1/2 inch is on the same level as the hoof wall).
5. The bars protrude no more
than 1-2 mm (less than 1/l0th of an inch) above the sole, becoming level
with the sole around the middle of the frog. They function as skid brakes,
and should under no circumstances bear weight (ie. grow to the level
of the hoof wall).
Only if these physiological
conditions are met can the hoof function in its biologically intended
capacity as shock absorber and pump (it is part of the circulatory system,
returning blood from the hooves to the body).
The coffin bone is suspended
inside the hoof capsule by the lamellae and surrounded by the bloodfilled
corium. When the hoof is picked up off the ground, the hoof capsule
is smallest and exerts pressure on the corium, thus emptying it of blood
(ie. pumping blood upwards, supporting the heart). On bearing weight,
the hoof capsule expands, the coffin bone descends and the sole spreads
outward/downward. As a result of this, the corium has more room (compare
5 mm to 2-3 mm when not bearing weight) and can, like a sponge, fill
with blood once again. When the foot is picked up, the whole cycle repeats.
Thus, with every step, the hoof pumps blood back toward the heart. This
pumping action is vital for optimal waste/nutrient exchange within the
tissues of the hoof, and supports the entire circulatory system.
Aside from this, the hoof
is responsible for shock absorption. This takes place through the expansion
of the hoof capsule and the spring-action of the suspended (not fixed)
coffin bone. In addition, the hoof contacts the ground first with the
softer areas (frog and bulb of the heel), adding additional shock absorption.
These vital functions of
the hoof are severely disrupted through the use of shoes. An expansion
of the hoof upon bearing weight becomes virtually impossible, since
the hoof does not expand only in the last third, but all the way from
the toe to the heel. As a result of this, the hoof receives only inadequate
blood supply and circulation, which leads to poor horn quality. The
ability of a horse to feel pain (or anything, for that matter) in the
foot is greatly reduced, since the nerves in the hoof receive insufficient
oxygen. With shoes, the hoof no longer impacts first on the softer shock
absorbing material of the frog and bulb of the heel, but strikes the
ground with hard, unyielding, non-shock absorbing metal.
In 1984, the Swiss Cavalry,
at the veterinary medical faculty of the University of Zurich, contracted
research into the effect of shoeing. Studies showed that the impact
force a shod hoof receives on hard ground is 10-33 times that of an
unshod hoof. The vibrations set up in the hoof by the vibration of the
metal shoe is approximately 800 Hz, compared to "only" 150
Hz with a rubber shoe.
However, shock absorption
and pumping action can also be insufficient in an unshod horse, when
the shape of the hoof is deformed (improperly trimmed) and/or the hoof
is too dry, and thus no longer elastic.
Copyright
Dr. vet. med. H. Strasser Blaihofstr. 42/1, 72074 Tuebingen, Germany
TeUFax: (011) 497071-87572 Ed. & Canadian contact: Sabine Naujoks
Box 44, Qualicum Beach, BC, V9K 1S7