Page 1136 - Adams and Stashak's Lameness in Horses, 7th Edition

1102 Chapter 11

created with the rasp placed at a 90° angle, starting on Shoes may be hand forged from steel or aluminum
the outer side of the sole–wall junction (white line). This bar stock or manufactured. Handmade shoes offer few
VetBooks.ir ates a sharp edge that is then smoothed with the rasp able on the market today. It is more important that the
advantages over the manufactured shoes that are avail­
manner of rasping reduces the hoof wall length and cre­
farrier be skilled at forging, so he/she can modify manu­
used in a horizontal direction, resulting in the rounded
perimeter. Flares, or excess toe, are removed from the factured shoes to fit the foot and hand forge a shoe from
outer hoof wall (shaping). The shaping is finished by bar stock when necessary. Heating the shoe makes alter­
slightly beveling the toe on the ground surface of the ing the shape much easier, and it has advantages when
foot from the toe quarters forward to decrease leverage, fitting the shoe, such as seating clips (when used) and
which promotes sole growth and to toughen the sole– detecting uneven sections on the ground surface of the
wall junction. This bevel should not be created if firm foot. Excessive heat generated by repeatedly placing a
pressure (using thumb pressure or hoof testers) on the red‐hot shoe on the horse’s foot should be avoided, as
sole causes the sole to deform. 13 the heat appears to damage the inner structures of the
The length of the adaptation phase often can be pre­ sole–wall junction.
dicted according to the initial structure of the horse’s Bar stock is usually rectangular in cross section and
foot and should be modified as necessary. When there is available in sizes from 0.6 to 1.2 cm thick and 1.2–
minimal sole depth (as evidenced by hoof testers applied 3.1 cm wide. The most common size is 0.8–1.9 cm.
to the sole), the horse should be confined or placed in a Concave bar stock has a crease stamped in the bar stock
small area of soft footing and walked daily on a firm and is tapered from the crease toward the inner margin
surface until the structures of the foot begin to change on the ground surface of the shoe. A shoe made from
and adapt. Placing the horse in a protective boot will this type of bar stock is thought to increase traction on
protect the foot but may not provide the necessary stim­ all terrains and possess a self‐cleaning action. It is fre­
ulation for adaptation. At no time should the horse quently used in Europe but has also become popular in
show marked discomfort, because this defeats the pur­ the United States. Pre‐made concave shoes can also be
pose. If the horse’s sole has not become firmer and purchased.
noticeable growth of sole does not appear on the inner Manufactured shoes, also referred to as keg shoes,
border of the sole–wall junction after 30 days, then it are catalogued using numerical sizes. Although the sizes
may be worthwhile to take lateral radiographs to assess are usually consistent within and between a given manu­
sole growth or reconsider whether this method of hoof facturer’s product lines, there is no universal standard
care is in the best interest of the horse. for sizing keg horseshoes. Manufactured shoes may be
generically shaped to the general shape of a horse’s foot
or specifically designed for a forefoot or hindfoot. The
THE HORSESHOE dimensions of the stock of both manufactured and
hand‐forged shoes affect the weight and stiffness of the
The basic configuration of a horseshoe is a curved shoe, coverage of the ground surface of the foot, height
bar made from a variety of materials that is rectangular to which the shoe elevates the foot off the ground, and
in cross section and shaped to conform to the contour of rate at which the shoe wears.
the ground surface of the hoof wall. The shoe should be Shoe weight influences the biomechanics of move­
wide enough to cover the ground surface of the hoof ment. The heavier the shoe, the more energy is
wall, the sole–wall junction (white line), and the sole expended accelerating and decelerating the limb at the
adjacent to the sole–wall junction. The shoe has four beginning and end of each stride. Therefore, the light­
surfaces: the foot and ground surfaces and the inner and est possible shoe should be used that is compatible
outer perimeter or margins. The parts of the shoe are with protecting the wall and adjacent sole and provid­
named after the corresponding section of the hoof: toe, ing the stiffness and wear required. Shoes made from
quarter, and heel. Each shoe has two branches, medial concave stock are lighter than those made from regu­
and lateral, that extend from the center of the toe to the lar bar stock. The width and thickness of the shoe usu­
medial and lateral heels, respectively. The width of the ally is uniform around the circumference of the shoe
shoe is often referred to as the web. The shoe is punched so that the biomechanical influences of shoe weight
or machine stamped with nail holes, three or four in and the stresses imposed are generally balanced about
each branch, 2–3 of which are generally used in each the axis of the limb. Although the width or web of a
branch. shoe is related to the thickness of the hoof wall, and at
least in part the size of the foot, it is common to
Materials and Size increase the width of the web of the shoe to provide
increased protection to the margins of the sole. The
Horseshoes may be made from steel, aluminum, tita­ thickness of the shoe is related to the rate at which it is
nium, synthetic polymers, or various composites; the expected to wear and to a lesser extent the rigidity
construction material dictates the shoes’ weight and needed to prevent the shoe from losing shape. The
durability. Most horseshoes are made of steel due to height that the shoe raises the foot off the ground also
their durability, cost, and workability. However, alu­ is influenced by the thickness of the shoe, but this is
minum is used frequently because of its lighter weight usually a secondary consideration.
and ease of shaping for many farriers. Recently, shoes Several common modifications are made to the
made from various synthetic polymers and composites ground surface of the shoe by forging, and some modifi­
have been recommended for specialty uses, but they cations can be made with an electrical grinder or sander.
have not replaced the traditional materials. Softening the 90° angles at the junction of the shoe’s