- Weight bearing is shared between the frog, bars,
caudal sole, sole callus and hoof wall.
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- Ground surface mass should be distributed so that
approximately 2/3 of the ground mass is behind the widest part of the foot and
1/3 is ahead of the widest part of the foot to the point of breakover.
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- The horses foot should land just slightly heel
first and the frog should be able to make primary ground contact.
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- The optimal point of breakover is found to be
approximately 1/4" ahead of the tip of the distal phalanx, as determined by
Radiographs. (Without Radiographs, the point of breakover is found to be the
back edge of the sole callus, usually about 3/4" to 1 1/2" ahead of the tip of
the frog depending on the size of the foot (000 - 5 respectively).)
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- Heels should be prepared relative to the live sole
and should end near the back of the frog.
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- The live sole callus is a protective mechanism that
extends ventral to the distal border of the distal phalanx and the circumflex
artery. It should always be preserved so that optimal protection and support is
provided for the distal phalanx.
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- When shoeing and trimming, it is important to
locate the live sole and to not invade that surface with a hoof knife.
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- When preparing the wall, to ensure good
medial/lateral balance, it is important to trim the wall equal on both sides of
the foot (at the toe and heels) relative to the live sole.
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- When applying shoes, the quarters of the hoof wall
are left flat. However, when trimming a foot that will be left bare, the
quarters will often be floated somewhat.
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- Hoof wall flares are only removed from the mid
portion of the hoof wall down.
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We hope that we
have been able to provide enough information in this tutorial to answer the
questions posed in the opening prologue. However, just in case the answers did
not fully reveal themselves, we have provided a few sentences to briefly
address each questions specifically.
|
| Q-1: Why does the
hoof wall always break at the quarters before the toe and heel? |
| A-1: The hoof wall breaks at the
quarters in most soft to moderately abrasive environments. The purpose served
by this design is to provide a trap for dirt in that area of the bars, frog and
whole caudal aspect of the foot. The frog apex is also accessible to the ground
for support as well. |
| Q-2: Why is there
frequently a small amount of callused frog present at the frog
apex? |
| A-2: The frog apex callus is
positioned very close to the center of the coffin bone. It is more noticeable
in flat feet and proliferates on demand. |
| Q-3: Why is there a
substantial frog build-up in the back part of the frog between the heels. Why
is this portion also heavily callused? |
| A-3: The calloused build-up at the
frog buttress helps to hold dirt in that area between the heels, which promotes
heel first ground contact upon landing. In turn, the proprioceptors proximal to
the callous become functional as well. Most importantly, support to the frog
buttress (callus) helps to absorb concussion, aide in circulation, and
participate in the alignment of the pastern with the distal
phalanx. |
| Q-4: What does a hoof wall
flare mean to the foot? |
| A-4: A hoof wall that does not
maintain a strait line from the hairline to the ground is not as strong as one
that is strait. The flare becomes more acute closer to the ground to encourage
easier removal by breaking and chipping. This is common with feet that are
allowed to grow beyond the sole level. |
| Q-5: Why is there a small
portion of the hoof wall below the coronary band at a different angle than the
rest of the dorsal hoof wall? |
| A-5: The area below the coronary
band that does not parallel the lower hoof wall is an indication of vertical
displacement, hoof deformity, and a more accurate indicator for the dorsal
angle of the distal phalanx. |
| Q-6: Why is there always a lip
of frog that forms on the ground surface of the frog? |
| A-6: The lips helps to hold dirt
firmly in the commissures of the frog to assist in the foot's
biomechanics. |
| Q-7: What purpose does the
raised area on the sole (just inside of the lamina) serve? |
| A-7: The live sole callus is a
protective mechanism that extends ventral to the distal border of the distal
phalanx and the circumflex artery. It should always be preserved so that
optimal protection and support is provided for the distal phalanx. |
| Q-8: Why is there always dirt
packed in the bottom of horse's feet, and particularly in the back
2/3? |
| A-8: The dirt compaction in the
caudal portion of the foot is a natural function of the life cycle of the foot.
The dirt's presence maintains a constant environment in and around the frog and
rear of the foot. The dirt compacts in the foot to help absorb concussion and
help maintain heel expansion. |
| Q-9: Why is thrush noticed in
feet and frogs that are narrow, with deep creases in the central
sulcus? |
| A-9: Horses that lead a less than
active life, are stalled most of the time and who's feet are cleaned regularly
are the ones that often have non-functional frogs that are narrow, stretched
forward and have contracted heels. It is theorized that thrush is as much of a
secondary condition to poor circulation as it is a bacterial problem. Horses
with essentially non-functional frogs have much poorer circulation and
therefore lead way to thrush susceptibility. |
| Q-10: Why do shoes always wear
more at the toe than the rest of the shoe? |
| Q-11: Why do the shoes wear
more rapidly at the toe when the foot appears to have a long toe, low heel
conformation? |
| Q-12: Why do most front shoes
wear more at the outside (lateral) toe? |
| A-10, 11, 12: The direction in which
breakover occurs is related to the direction in which the knee bends. The horse
will fulcrum over the front limbs with every step. Toes that are longer are
subjected to more force at the time of breakover as well as are worn quickly by
a toe first landing. |
| Q-13: Why does the frog and
sole change to hard and soft textures rapidly when the weather changes?
|
| A-13: The sole, frog and bars are
major support members in the foot, therefore they adapt to protect the foot
when adversities occur. |
