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From: tom.stovall@darkhrse.sccsi.com
Subject: Horseshoeing FAQ
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Disclaimer: this FAQ is in response to numerous Email requests. It is
intended to be generally educational and deals with the reasons for
shoeing and basic materials used in modern farriery. It should not to
be considered specific to any breed, type or individual. It is not
copyrighted and may be freely distributed, copied or whatever.
Tom Stovall
American Farriers Association
Journeyman Farrier
There are only three valid reasons that horses are shod: protection,
traction or to change the way a horse moves.
Protection is the most obvious reason: Simply put, if a horse's rate of
foot wear exceeds his rate of foot growth, his foot must be protected
in some way. If not protected, continuing the same routine, in the
same environment, will cause soreness. Once sore, the owner can either
lay him up while he grows out enough to protect himself with hoof wall
and exfoliating sole, or shoe him and accomplish almost the same thing
artificially.
The most obvious form of protection is a horseshoe. But, what kind of
horseshoe? Horseshoes are made from rubber, plastic, steel, aluminum,
titanium and occasionally from other materials ranging from brass to
rawhide.
The most common type is steel. Steel horseshoes are readily available
and easiest to use. They can be easily modified or forged from bar
stock with only minimal forging skills. Steel is easily welded or
brazed for specialty applications. Steel comes in a variety of widths,
thicknesses and configurations. Many farriers die of old age without
ever nailing on anything but steel shoes. Occasionally though, horses
need other kinds of shoes.
Aluminum has found widespread acceptance in flat and harness racing, and
on the fronts of speed event (e.g., barrel horses) where weight of the
shoe is an important factor. Aluminium is also very popular on the
fronts of hunters as many trainers feel it enhances a hunter's way of
going. It is also the first choice of many veterinary farriers as its
greater width and thickness (relative to steel) can be used for
protection of sensitive structures without adding weight. Aluminum is
not quite as easy to forge or weld as steel.
Solid rubber and plastic shoes have very limited specialty applications
(e.g., horses used for drayage on hard surfaces, pathological
conditions). Full (covering the sole) synthetic shoes trap moisture and
create ideal conditions for Thrush; rim-type synthetic shoes simply
don't stay where they are put: they have an embarrassing tendency to
shift and extrude. Open, (sole not covered) rubber and plastic covered
steel, often with factory-made clips, are the best choice of this lot.
Titanium is sometimes used on horses that need a light, very strong shoe
in front. Usually, either big race horses which routinely bend aluminum
(usually the near fore) or jumpers and barrel horses which must make
sharp turns at speed. Titanium is easily forged or swedged into
specialty configurations, but must be TIG welded. As this once very
costly metal becomes cheaper, it is gaining popularity for routine use
in speed horse farriery.
Historically, brass shoes were nailed on with brass nails and used in
explosive atmospheres (e.g., mines).
Horseshoes have two basic configurations, open-heeled shoes and bar
shoes. These basic types have an infinite number of variations which
may be tailored to the individual animal. To further complicate things,
a shoe may have various accoutrements: clips, calks, jar-calks,
screw-ins, bubbles, grabs, etc. Hopefully, these serve some purpose and
enhance a particular aspect of the shoeing job.
Also under the heading of protective devices, are the various types of
metal, leather and plastic pads and the many substances which are packed
between pad and sole for various cushioning and medicinal purposes.
Pads come in two basic types: full or rim. These, in turn, come in two
configurations: flat or wedged.
A full pad covers the entire sole; rim pads usually just the area
immediately beneath the shoe. A special kind of rim pad, called a
bar wedge pad, covers most of the frog area, but is open toward the toe.
Most flat pads may be from one-eighth to one-half inch thick. Wedge
pads are sold in one to four degree elevations (thick at the heel,
tapering to toe) which increase angulation. Pads are made from leather
or synthetic (rubber or plastic) and may be soft or hard. Since leather
is sensitive to moisture, it is seldom used in horses which are
routinely turned out.
Most pads are placed between the shoe and foot although some special
veterinary applications are fabricated from metal and bolted to the
ground surface of the shoe.
Multi-pad applications (stacks) are used in long-footed horses
(Saddlebreds, Morgans, Tennessee Walkers, etc.) primarily to enhance a
particular way of going and only incidentally for protection.
The substance placed between a full pad and sole is called "packing".
Packing takes many forms and usually consists of a two-part application.
First, some kind of medication is painted on the ground surface of the
foot. This may be a proprietary preparation (e.g., Durasole [tm],
Reducine [tm]) or a "secret" mix preferred by an individual farrier.
Most are iodine-based and antifungal and/or antibacterial in nature and
aimed at retarding the growth of pathogens in the sole and frog.
Next, the packing is placed between pad and sole, and the shoe nailed
on. The basic types of packing are: oakum, sponge or foam, uncured
rubber, silicone and various types of catalytic hardening soft acrylics.
In addition, packing may consist of a mud-like medicated poultice.
A traction device is anything added to a shoe to enhance or increase
traction. These take innumerable forms: special nails, heel calks,
toe calks, grabs, jar calks, swedges, Memphis bars, etc.
Several special types of horseshoe nails are used for traction. Most
are large-headed nails which protrude below the ground surface of the
shoe. Mud and ice nails are two of the better-known configurations;
however, an emergency traction device might consist of something as
simple as a regular head nail used in a shoe punched for city heads.
Heel calks consist of downward projections of the shoe, located behind
the heel nails. Their design is limited only by the farrier's
imagination and the rule book for a particular breed. They are either
forged (a part of the shoe), built up with foreign material (e.g.,
Kutrite [tm], borium), "screw-ins" or "drive-ins". Calks are usually
applied singly (to the outside heels) or in pairs.
Toe calks are protuberances placed ahead of the toe nails. They are
attached in the same way as heel calks with the exception that few are
forged. A grab may be either forged or welded/brazed to the toe of the
shoe. it usually consists of a relatively thin projection placed
lengthwise, between the toenails. Technically, a grab is considered a
kind of toe calk.
Jar calks are usually placed across the web (width of the ground
surface) of the horseshoe. They are usually used more to send the foot
in a certain direction than as a pure traction device. They are often
used singly at the toe; in pairs at the heel. However, the most common
usage is the familiar "mud calk" or "sticker" hind race plate which
consists of a single, outside heel jar calk.
Swedge refers to a lengthwise indentation in the web of the shoe.
In theory, the swedge fills with dirt which gives more traction than the
parent material of the shoe alone. The ridges formed by the swedge may
be the same height (rim shoes), higher outside (barrel racing shoes,
Levelgrip [tm] race plates) or higher inside (polo shoes, "Argentine"
race plates). The swedge is used to increase traction; the relative
surface heights created by the swedge, to determine breakover.
A Memphis bar is a narrow piece of metal welded/brazed (usually, not
always) across the quarters of the shoe. They are usually used singly,
across the toe quarter, and on hinds. Their main purpose is traction/
breakover on long-footed horses.
Each traction device may be used in conjunction with others; thus, the
usage may be customized for an individual animal to suit a specific set
of circumstances. For example: a flat racer running on a sloppy track
might be shod with a grab and sticker behind, and a grab and jar calks
in front. The same horse, on a dry track, might run with only a grab
behind and rims in front.
The final reason to shoe a horse is to change a horse's way of going.
Usually, a farrier will try to change an animal's way of going for one
of two reasons: either to stop the horse from hitting (interfering in
some way) or in an attempt to modify a particular gait to better meet an
arbitrary (subjective) standard, usually related to a particular breed.
The specifics of this particular aspect of farriery require particular
expertise and are beyond the scope of this overview. In general terms,
a gait may be modified by changing the way a foot leaves the ground
(breakover) or its behavior off the ground (flight path). These factors
are changed by the removal/application/utilization of weight and length.
A gait may also be modified by changing the timing relative to opposite
members; e.g., fronts to hinds.
A horse will do whatever he does most efficiently if he is balanced,
both fronts and hinds, in the two basic planes (anterior-posterior;
medial-lateral) from the fetlock to the ground. Recognition, analysis
and treatment of gait aberrations are some of the most difficult tasks
facing the farrier.
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