Is Your Horse Shod Right?
By
Don Blazer
Copyright © 2002
Lesson Two
Never abdicate the
responsibility for your horse’s feet to a farrier or a veterinarian.
And do not leave
your horse’s foot to the whims of nature.
Your horse is not in a natural state.
He is not a wild horse. The
natural foot of a wild horse is not in the least relevant to your horse.
Knowing correct
foot balance, and knowing what a horseshoe can and cannot do for the balance
and protection of your horse’s foot is your responsibility.
Using the chart
provided, (Your hoof balancing chart will be found at
the end of this lesson.) examine your horse’s feet. Measure and write on the chart the dorsal
(toward the front) and palmar (toward the rear)
distances from the middle of the frog. Measure and note the medial (inside) and lateral (outside)
distances from the center of the frog to the edge of the hoof wall. Make notations of hoof wall dips, flares and
cracks. Note the thickness of the hoof
wall, the condition of the sole and frog, the width of the heels and how even
and level the coronet band of each foot.
You will also measure the distances from A to B and C to D for each
foot. These measurements are guides to
overall foot balance.
Having charted your
horse’s feet on a given date, you now have a reference to guide you in working
toward both balance and health for the foot.
HOOF BALANCE
We can
define a balanced hoof as one which has both the shape and strength to support
the horse while providing the basis for optimum (efficiency of) movement.
This definition
relates directly to the definition of good conformation—form designed for
function.
We know that
horsemen often seek conformation not for efficiency of movement, but for
specialized movement. Horsemen do
exactly the same thing with the horse’s hoof, abandoning the shape and strength
of efficiency to produce a particular stylized movement. In both cases those are choices.
It is my choice to
seek a balanced foot and optimum efficiency in movement.
Each time the horse
moves, each foot is subjected to a collision with the ground, concussion and
compression. Each step—because of
differing ground conditions—tends to work against the balance of the foot,
pounding it, pressing it, twisting it.
Such forces are also detrimental to the health of the hoof.
The horse shoe
should be placed on the foot to protect the hoof from damage and to bring the
hoof into balance.
Faulty foot balance
precludes optimum movement and directly contributes to bone-chip fractures, a
navicular condition, shortened strides, bad backs and sore muscles.
ANATOMY OF
You
should have a basic knowledge of the hoof and related structures. The cannon bone, sesamoids
and long pastern affect the foot by alignment and formation of the fetlock
joint. The pastern, shoulder and hoof
angles (slant) should all be the same.
The short pastern
is partially within the foot and is jointed with the coffin bone (distal
phalanx, P-3, or pedal bone). You should
also be aware of the lateral cartilages, navicular bone, plantar or digital
cushion and the frog.
Other parts of the
hoof which are of concern are the coronary band, the periople,
the hoof wall (capsule), the white line, the insensitive laminae (which grow
inward from the interior of the capsule wall) and the sensitive lamina (which originate
from the coffin bone). The insensitive
and sensitive laminae link together to actually support the weight of the horse
and absorb concussion. The linking of
the laminae actually holds the horse’s coffin bone from plunging down through
the foot. When laminitis occurs the
linking of the insensitive and sensitive laminae can be torn apart which allows
the “sinking” or rotation of the coffin bone.
ASSESSMENT
OF THE HOOF
Begin by looking at
the coronet band of each foot. The hair
line should be even and virtually level, dropping off slightly as it rounds the
foot toward the heel. An uneven coronet
band, with high spots or dips, indicates health problems and/or an uneven hoof
capsule.
Looking
at the horse from the front, use a long ruler or T square to create a line
through the centers of the joints of the knee and fetlock and the center of the
hoof. The line should be
straight. Deviations of the knee, cannon
and fetlock should be noted since they will have a direct relationship to the positioning
of the hoof.
Move to the side of
the horse to determine the weight bearing point at the heel. Place your thumb on one side of the widest
point of the cannon bone and your index finger on the other side. Now gently run 
your
fingers down the cannon bone and onto the fetlock joint. Where your fingers rest in
the middle of the fetlock joint should represent the center of the rotation of
the fetlock joint. A vertical
line dropped directly to the ground from that point should brush the hoof wall
heel. If the heel hoof wall touches the
ground in front of the line, the horn tubules of the hoof wall have probably
been crushed under, and the heel is under run. The hoof horn tubules at the toe
and heel should be parallel.
Imagine a line
running through the center of the pastern to the coronet band. Put your finger on the coronet band at the
point where the imaginary line strikes the coronet. That point is very close to the center of the
rotation of the short pastern and the coffin bones. If you drop a vertical line straight down
from that point to the ground, the line should bisect equally the weight
bearing portions of the foot. It is easy
to measure the distance forward to the toe and rearward to the heel at ground
surface.
The weight of the
horse should be centered between the toe and heel. If the distance to the toe is longer than the
distance to heel at ground surface, or vice versa, then there is no dorsal/palmar balance.
A lack of
dorsal/palmer balance is the most frequent hoof imbalance and is almost always
the result of poor shoeing practices.
The shoer applies a shoe which is too small to
provide palmar distance for balance and is inadequate
to protect the hoof capsule at the heels.
If the weight bearing portion of the
hoof, or the horse shoe does not extend as far behind the weight of the horse
as the toe extends in front, then everything collapses backward, creating the
under run heel.
A shoe too short to
provide adequate dorsal/palmar balance is generally
used because it requires little shaping and there is very little chance the
horse will catch it with a hind foot and pull it off. Horse shoers do not
like to make their clients unhappy by having shoes come off, and horse shoers do not like return trips to replace lost shoes
because such trips reduce their profit margin.
Horse shoers generally do not trim the foot adequately
(especially the toe) because they do not want to risk the horse being a bit “ouchy.” It’s very
unfortunate for horses that from a business viewpoint it is better to have an
unbalanced hoof than an unhappy horse owner. I
am not suggesting that a horse should be “ouchy” just
after being shod. It is a fact, however,
that freshly exposed horn can be a bit sensitive.
When a foot is left
“just a little long” each time to avoid the possibility of tenderness, the foot
eventually gets “much too long”, and is then out of balance.
Using the T-square
or long ruler, stand in front of the horse and sight down the cannon bone. The T-square should bisect the cannon and the
hoof. From this vantage point it is very
easy to see knee, ankle, pastern and hoof deviations.
You can also stand
beside the horse at his shoulder and with your hand just behind the horse’s knee
pull the horse’s leg upward and forward.
Let the horse relax and just hang his leg. Now site down the cannon and you should
easily be able to see how the hoof is centered in relation to the cannon
bone. There should be equal amounts of
hoof on each side of your sight line.
Gently allow the
horse’s leg to lower to the ground, just barely touching hoof wall to the
ground. The point at which the toe meets
the ground is the horse’s natural break over point, and should be the mark for
the center of the toe of the shoe. If
the foot is in balance, the apex of the frog will point directly at the natural
break over point. If the natural break
over point and the apex of the frog are not in alignment, then the foot does
not have the proper shape and balance.
When looking at the
hoof from the front, the angle of the lateral and medial walls should be the
same. It is often suggested the medial
hoof wall should have a steeper angle than the lateral side, but this is incorrect. (The suggested steeper medial hoof wall
originates in the idea that it must support more of the horse’s weight which is
greater at the center line of the horse.)
While the medial side of the cannon bone is often more stressed than the
lateral side, it should not affect the hoof. The hoof wall medial/lateral angles must be
nearly equal in order for the foot to remain in balance.
The differences in
the medial and lateral hoof wall are often the result of a common hoof
balancing error, the unleveled trimming of the foot.
Holding the horse’s
front foot between his legs, the shoer pulls the
horse’s foot away from the horse’s body.
Viewing the foot from this angle rather than from directly under the
horse’s body distorts the perspective of the level of the foot.
Unless great care
is taken to be sure the trim cuts create a level foot, it is almost a certainty
the lateral side of the hoof will be longer than the medial side.
If this is the
case, the lateral side will flare and/or have a dip in the middle of the wall,
and the medial side will become more upright.
The medial/lateral
hoof wall lengths must be equal before any hoof balancing can take place.
Never allow the horse’s hoof to be cut to
a pre-determined angle. The hoof must be
cut to match the angle of the shoulder and pastern.
Researcher and veterinarian Daniel Marks
says conclusions upon reviewing various studies shows front hoof angles will
actually range most often from between 54 and 58 degrees rather than the
commonly accepted 45 degree angle. The lower the hoof angle, the more stresses
are placed on the posterior portion of the hoof and limb.
The feet should be symmetrical with the
front feet having a slightly lower angle than the hind feet which most often
will be near 58 degrees, says Marks.
Shoeing a performance horse more toward its best foot conformation would
be helpful in successful performance.
For example, in a study of 95 racing Thoroughbreds, those shod with the
higher angle were likely to win more and have less injury, Marks concluded.
HEELS
It was once believed that upon weight
bearing the frog was pushed up, in turn causing the heels to expand. We are now aware that the back end of the
coffin bone rotates downward as the hoof bears weight, and it is this downward
action which expands the heels.
The hoof is
dynamic, constantly moving as it absorbs concussion and compression. The heel of the foot expands and contracts
with each step.
Because a long toe,
low heel is the second most common balance problem, many shoers
fail to trim the heel properly, leaving it excessively long. When the heel is not trimmed to the proper
length it adds to the long toe, low heel problem because the untrimmed heel
forces the horn tubulars forward, eventually
resulting in under run heels. Excessive
heel length must be trimmed away to assure a healthy hoof. It is
absolutely necessary to trim the heel low enough to allow the frog to rest on
the ground when the shoe is in place.
Do not allow the frog to be trimmed
away, or the hoof wall to be left so long as to allow the frog to atrophy and
fail to rest on the ground. The frog
must be left so that it is at the same level as the shoe. This is the only way the frog can function
properly as a support to interior structures and as a ground gripping mechanism
for support and movement of the horse.
It is absolutely
mandatory the horse shoe be wider at the heel than the hoof capsule. The extra width—at least the width of a dime,
allows the foot to expand while having continued protection and support.
All hoof imbalances affect the orientation of all
joints.
All the joints of
the horse’s legs are ginglymus joints, meaning the
bones are shaped to hold their position.
It is easy to see that
if the hoof is unleveled, uneven stress is placed on the joints. Damage to cartilage and eventual arthritis is
the normal result.
If the horse’s hoof
is properly balanced, then you should see a straight hoof/pastern axis. Imagine a line running through the center of
the pastern and the hoof.
If the line is
straight, then the hoof/pastern axis is straight.
If the line running
through the pastern is bent upward when it passes through the coronet band and
into the hoof, then there is a broken back hoof/pastern axis. This is the condition seen when a long toe,
low heel exists.
If the line running
through the pastern is bent downward as it passes through the coronet, then the
hoof/pastern axis is broken forward.
This is the condition seen when the heels are too high.
HIND FEET
The hind feet
should have a slightly more elongated shape than the front feet. The front feet act as a stabilizing platform
over which the mass of the horse travels as the horse moves.
The hind feet are
used by the horse to propel him forward.
The elongated shape digs into the ground, providing more efficient
traction.
When
viewing the hind feet from the front, you should notice the toes point outward
just slightly. As a horse moves with
speed, the hips and hocks rotate outward, while the toes rotate inward. If the toes pointed straight ahead when the
horse was standing, they would rotate into a position likely to strike the
front legs when the horse was in movement.
If they turn out slightly, they rotate into a straight position during
movement.
When trimming the
hind feet, the shoer must follow the balancing
guidelines, trimming both the heels and the toes in a ratio that creates a
straight hoof/pastern axis.
CHECKING THE
CHARTS
Once you have
charted your horse’s feet you will have a guide for proper shoeing.
On the front feet,
the distance from A to B should not be longer than C to D. Having the A to B distance the same as the C
to D distance is the ideal front foot shape for maximum efficiency and
strength.
If the A to B
distance is shorter than the C to D distance, you can create the ideal shape by
allowing the shoe to extend (shoe extensions) past the hoof wall slightly at
the A and B points. Extensions should
not be excessive. Horses in stalls or
traveling in trailers frequently step on shoe extensions and pull the shoe.
On the hind feet,
the distance from A to B should be shorter than the distance from C to D, but
not by more than 10 per cent.
When the feet are
out of balance, there can be several obvious physical results.
Forging is the
result of too long a toe in front, in back or in both. Forging occurs when the toe of the hind foot
strikes the sole of a forefoot. This
happens because the long toe on the forefoot delays the front hoof break over.
Overreaching is
also the result of too much toe. In
overreaching, the toe of the hind foot actually hits the soft tissue of the
heels of the front foot. Severe injury
can be caused by overreaching.
Scalping occurs
when the pastern of a hind leg is struck by the toe of a forefoot. Scalping can also cause severe injury and
obviously has a very detrimental affect on a horse’s performance.
Speedy cutting is
very similar to scalping. In speedy
cutting the inside of the fetlock joint and/or pastern of a hind leg is struck
by a forefoot. Again performance is
affected and injury can be severe.
There are basically
six types of horseshoes, each of which has a specific use.
There is the
standard shoe in steel or aluminum, normal or wide web. This is the most commonly used shoe and
unless there are specific problems to be addressed, it serves its purpose of
protecting and aiding hoof efficiency.
The egg bar shoe is
used when the horse’s heels have collapsed.
The egg bar provides about 25 per cent more ground surface at the
heels. The egg bar should extend as far
back as the bulbs of the heels, just as a standard shoe.
The egg bar is
frequently used on navicular horses.
While the egg bar shoe may indeed help the navicular horse, the aid
comes not from the shoe, but from the fact the foot has been returned to a
better balance.
Navicular horses
often have under run heels, and when they do, the egg bar shoe is the best
choice.
The first
consideration for the navicular horse should be restoring hoof balance.
The straight bar shoe
is used on horse’s with sheared heels (one heel higher than the other), or when
there is any other type of breakdown of the tissue between the heels. When there is a tissue breakdown, the bulbs
of the heels move vertically causing the horse pain.
The straight bar shoe immobilizes the heels reducing the pain
factor. To be totally effective,
however, the hoof of the horse with sheared heel must be trimmed so the
elevated heel bulb can drop back into a balanced position.
The half-bar shoe
is used when the hoof capsule, due to imbalance, has started to spiral around
the foot creating a situation where one side of the foot needs more support
than the other. This is usually the
medial side. The shoe must be fitted so
the half-bar extends over the frog and adds support to the side of the foot
bearing the most weight.
In some cases the
ground surface of the foot which is taking all the weight has started to flare
out, while the opposite side has rolled under and is inside a vertical line
dropped from the coronet band.
The heart-bar shoe
is commonly associated with laminitic horses. The effectiveness of heart-bar to support the
coffin bone is debatable at best.
The most effective
use of the heart-bar is with the flat footed horse. When the horse has no concavity to the sole,
the heart-bar keeps the sole from becoming convex and tearing away from the
hoof wall.
To determine if the
frog plate pressure is acceptable apply the heart-bar with only two heel
nails. Then lift the opposite foot and
determine if the horse stands comfortably on the foot with the heart-bar. If the horse accepts the pressure, then the
shoe can be nailed into place.
When a heart-bar is
used, the horse manager must be careful to clean thoroughly under the bar so
thrush does not develop and damage the frog.
The combination
egg-bar and heart-bar shoe is used on horses which have both flat feet and long
sloping pasterns. Horses with this
conformation are prone to have under run heels.
Shoe extensions
should be used to correct medial/lateral balance. Check the chart on your horse’s feet and if
the distance from the center of the frog to the medial or lateral side is
greater than to the opposite side, then an extension is needed. An extension may not be able to bring the
foot into perfect balance the first time it is applied. However, if extensions are applied with each
shoeing the hoof will eventually balance out.
A horse may not
show obvious signs that his feet are hurting, especially if he is hurting
equally in both front or all four feet. Horses with sour attitudes about work, or
with sore backs or backs with muscle atrophy should have their feet checked and
charted immediately. It is a safe bet the
horse’s feet are out of balance.
If a horse has flat
feet, have the shoer attempt to narrow the feet and
use wide web shoes.
Navicular horses
can be helped by bringing the feet into balance—especially dorsal/palmer
balance. The use of wide web shoes can
also add to the horse’s comfort.
Hoof cracks should
be grooved out so the sides of the cracks do not touch or rub as the hoof
expands and contracts.
Heel wedges are
neither necessary, nor advisable as they crush the heel further, creating
greater damage. Instead of heel wedges,
use an egg-bar shoe.
These photos show
how damaging wedged pads can be to a horse’s heels.
This horse had been shod in wedge pads for nearly three years. (Click
Here to See Photo.) Trimming for hoof balance and reversing the shoe
(similar to using an eggbar) to provide heel support
allowed this horse to travel more comfortably within 20 minutes of having been
re-shod. (Click
Here to See Photo.)
If a horse has a
major sole bruise or a puncture to the sole, then the use of a pad is advisable
for a short period of time. The use of
pads is not advisable as most of the time they simply hide problems which
should be addressed and corrected.
For horses which
will perform on slippery surfaces, such as grass, the use of studs is
advisable. However, the studs must be
removed immediately after the performance.
As a horse owner
you should be able to recognize a well shod horse, and you should demand your
horse be well shod.
Knowing correct
hoof balance and knowing how it can be achieved is your responsibility. It is not necessary you be able to shoe the
horse yourself, so don’t be intimidated or harassed by a shoer
who ignores your requests. With a little
effort you can find a shoer who will apply his skills
for the benefit of your horse.
Ask for advice,
seek opinions and differing ideas, research hoof health care, but make your own
decisions as to how and when your horse is to be shod.
Observation and
continual charting of your horse’s feet can add years of enjoyment and
soundness to his performances and his life.
NO
SHOEING FOR PERFORMANCE
by Haydn Price & Rod Fisher
HORSESHOEING THEORY
