PREPARATION OF THE FOOT.
The cheap wisdom of the amateur is often expressed in the remark "the
shoe should be fitted to the foot, not the foot to the shoe." Like
many other dogmatic statements this is only the unqualified assertion
of half a truth. Foot and shoe have to be fitted to each other.
There are very few horses whose feet do not require considerable
alteration before a shoe can be properly fitted to them. As a rule,
when a horse arrives at the forge, the feet are overgrown and quite
out of proportion. In a few cases--as when a shoe has been lost on a
journey--the foot is worn or broken and irregularly deficient in horn.
In either instance the farrier has to make alterations in the hoof to
obtain the best bearing surface before he fits a new shoe. The claim
often made for some novel inventions in horse shoes, "that they may be
fitted and applied in the stable by a groom or stableman" is evidence
of a sad misunderstanding of the art of horse-shoeing. If shod feet
always remained of the same shape replacement of shoes would be a very
easy matter--but they never do. The living foot is constantly changing,
and therefore the man entrusted with fitting shoes to it, must know
what its proper form should be. When he finds it disproportionately
overgrown he must know how much horn to remove--where to take away
and where to leave alone. He must not carry in his head a theoretical
standard of a perfect foot and attempt to reduce all feet to that
shape. He must make allowance for varieties of feet, and for many
little differences of form that present themselves in practice. He has,
in fact, to prepare the foot for a shoe, and it is just as important
to do this properly as it is to prepare a shoe for the foot. To fit a
shoe to a foot which has not been properly prepared may be even more
injurious to the horse than "to fit the foot to the shoe."
The general principle to be followed is--to remove superfluous horn,
to obtain a good bearing surface for a shoe, to bring all parts of the
hoof equally into proportion. A good foot so prepared, when the horse
is standing on level ground should show, when looked at from the front,
both sides of the wall of equal height; the transverse line of the
coronet should be parallel with the line of the lower border of the
hoof, and
the perpendicular line of the leg should cut those lines at right
angles. (Fig. 17). When looked at from the side the height of the heels
and the toe should be proportionate. When looked at from behind the
frog should be seen touching the ground. On lifting the foot a level
bearing surface wider than the wall should be presented, extending from
heel to toe all round the circumference of the hoof; within this level
border, the sole should be concave, strong, and rough.
[Illustration: Fig. 17.]
In Fig. 17 is shown the foot on its ground surface and from the side.
The parallel lines are quite arbitrary, but assist in explaining how
the proportion of the foot is to be attained. Both sides of the foot
are of the same height. The bearing surface just meets the middle line.
All the lines at coronet, heel, and toe, are at right angles to the
perpendicular line. The side view shows the proportionate height of
heel and toe, and the slope of the wall in front. Compared with Figs.
22 and 23 deviations from proportion are seen.
These conditions are not attainable with all feet, but the prudent
farrier does the best he can under the circumstances. It is easy to
make the frog touch the ground by over-lowering the heels, but this is
only introducing one evil in attempting to avoid another. Some feet
have naturally a long toe with an excessive slope of the front part
of the wall. To hide this defect a farrier may "stump up" the toe and
leave the heels too high, but he does so at the expense of the horse's
foot. Each foot requires treating with full knowledge of the form best
adapted to its natural formation, and most capable of carrying a shoe.
=The Instruments= used to prepare a foot for shoeing are a rasp, a
drawing knife, and a toeing knife.
The rasp is the most indispensable. It should be sixteen inches long,
proportionately broad, and one part of it should be a file-surface. The
shorter, narrow rasps do not afford all the advantages a farrier should
possess to enable him to do the best work. To strike an even all-round
level bearing surface on a hoof a farrier requires a large rasp, just
as a joiner must have a large plane to produce a level surface on wood.
Harm may be done by the careless use of a rasp, and a bearing-surface
spoiled by the over-reduction of horn at one place. This fault may be
aggravated by attempts to mend it, if such attempt take the form of
further reduction of the whole hoof on a foot where horn is deficient.
The drawing knife is a comparatively modern instrument which replaced
a tool called the buttress. A drawing knife is formed with great skill
for the purpose of paring out the concave sole of the hoof, and has
done infinite harm. In the days which have now almost passed away,
when it was thought the proper thing to make the hoof look clean,
smooth, and pretty, the drawing knife was the chief instrument in
the preparation of the foot. Now, when nearly all men know that the
stronger the sole and frog of the foot can be preserved the better
for the horse, this knife is less used--and the less the better. The
doorman, preparing a foot for the fireman to fit a shoe to, should
not use a knife at all. The man who fits the shoe requires a knife to
remove occasional little prominences of horn which are liable to cause
uneven pressures or which are in the way of a properly fitted shoe--as,
for instance, the edge of the wall to make way for a clip, or the angle
of sole at the heel to prevent uneven pressure by the shoe.
The toeing knife usually consists of about a foot of an old
sword-blade. This knife is held and guided by one hand of the farrier,
whilst with the other it is driven through overgrown horn by the
hammer. Skilfully used it is unobjectionable, and for the large strong
hoof of heavy draught horses it saves a great deal of time and labour.
For the lighter class of horses it is unnecessary, and for weak feet
with a thin horn covering it is dangerous.
The toeing knife cannot leave a finished level bearing surface, and
its work has to be completed by a few strokes of the rasp. A farrier
should, therefore, never attempt to remove all the superfluous horn
with the knife, he should leave some for the rasp so that in producing
the final level surface no encroachment upon the necessary thickness of
covering horn need be made.
[Illustration: Fig. 18.]
=The overgrown foot= such as we find on a healthy horse that has
retained a set of shoes for some weeks, or that has been without
shoes on a surface not hard enough to cause sufficient wear, is quite
unfitted to receive a shoe. It must be reduced to proportions. In
Fig. 18, I have attempted to show diagrammatically a side view of
an overgrown hoof. The dotted lines at the base show two effects of
lowering one part more than another, although both attain a level
surface. In Fig. 21 we see the result of over-lowering the heels, and
in Fig. 20 of leaving them too high. It may also be noticed that these
conditions affect other parts of the foot; in fact not only other parts
but the whole foot, and even the relative position of the foot to the
leg. If we compare the proportionate foot, Fig. 19, with the diagram
Fig. 21, it will be seen that by over-lowering the heels the slope
of the front of the foot is increased, that the bearing surface from
heel to toe is slightly increased in length, and that if the dotted
perpendicular line be accepted as showing the direction through which
the weight of the body passes, lowering the heels tends to put an
increased proportion of weight on the back parts of the foot. If we
compare Fig. 19 with Fig. 20 we see the effect of leaving the heels too
high. The bearing surface from heel to toe is shortened, the slope of
the wall at the toe is made less, and more weight is thrown upon the
front parts of the foot.
[Illustration: Fig. 19.--A proportionate hoof.]
[Illustration: Fig. 20.--A disproportionate hoof--heels too high.]
[Illustration: Fig. 21.--A disproportionate hoof--heels too low.]
Now these alterations in both cases affect not only the form of the
foot but its relative position to the leg, and as the bones of the
limb above are a series of levers connected by muscles and ligaments
so placed as to be most efficient for movement, it is evident that
alterations of the foot must affect the action of the limb. (Compare
Figs. 19, 20 and 21) In the unshod horse roaming about there is a
natural automatic return to proper relative position whenever it has
been temporarily upset. A long toe is worn down and high heels are
reduced to their proper level by friction. Not so a foot protected by
an iron shoe. Wear is stopped, and a disproportionate hoof becomes more
and more disproportionate. Temporary alterations of the position of the
foot do little harm because they are permitted, within a margin, by the
movement of joints and by the elasticity of muscles. When, however, an
alteration of position is continued for many weeks it tends to become
permanently fixed and may thus do a great deal of harm, which is not
traced to its real cause because the effect is slow and gradual. It is
important, therefore, to remember that the proportion of the hoof is
to be maintained not only because it is necessary to the well-being of
the foot; but because it affects the action of the whole limb. Too long
a toe may cause a horse to stumble, and it must always increase the
strain on the back tendons during progression. Heels too high prevent
the frog from taking its proper bearing on the ground, and thus cause
a loss of function in the back parts of the foot. An excessively high
heel has a tendency to throw the knee forward and to straighten the
pastern.
[Illustration: Fig. 22.--Heels high--under surface and side view.]
[Illustration: Fig. 23.--Heels low--toe long.]
It is impossible to lay down any hard and fast rule to guide a
farrier in maintaining the proportions of heel and toe when reducing
an overgrown hoof to proper form. Feet differ much in their natural
formation, some are high-heeled and some low, some are straight in
front some very much sloped, some are narrow and upright, others round
and spreading. In Fig. 22 the heels are too high, and the bearing
surface does not reach the transverse line at the heels. The side
view shows the excessive height of heels and the slope of the wall in
front too upright. Great assistance is afforded the farrier in judging
whether he should remove more horn from heel or toe by the appearance
of the under surface of the foot. When the heels are much above the
level of the frog there is an indication for their lowering. When the
wall and bars are about flush with the angle of sole between them,
there is, as a rule, no more horn to spare at that part. The length of
the toe may be usefully gauged by the condition of the junction between
wall and sole. When the sole is sound and strong all the wall above its
level--wall unsupported by sole and showing on its inner aspect marks
of the horny laminæ--may be rasped down so that a firm bearing surface
is obtained consisting of wall and sole.
In Fig. 23 the bearing surface at the heels is below the line marking
a proportionate foot. The toe is too long and projects beyond the
transverse toe line. The side view shows the low heel and the
corresponding excess in the slope of the wall in front. The lower
transverse line in each figure does not represent the ground, but is
added to make clear the height of heels and length of toe.
Important as it is to maintain the relative proportions between the
front and back parts of the foot, it is perhaps even more important
to preserve the balance between the two sides of a foot. Both sides
must be left of equal height. If one side be higher than the other a
disproportionate amount of weight is thrown on the lower side, and more
or less strain is put upon the ligaments of the joint above. In the
Figs. 24 one limb is shown with both sides of the hoof even, and the
straight line of the limb cuts squarely across the transverse line of
the bearing surface of the foot. In the the other limb one side of the
hoof is too high, and in the preparation for shoeing only that side
will require attention.
[Illustration: Fig. 24.]
Through constant neglect of this point some feet become more or less
permanently twisted--and the twist occurs at the coronet. The ground
surface of a foot or a shoe always tends to remain at right angles to
the direction of the limb, and when the sides of a hoof are allowed to
remain of unequal height, the higher side presses the soft tissues of
the coronet upwards. As the hoof grows from the coronet the side thus
increased in height is not so noticeably uneven at the lower border of
the wall as at its upper, and it cannot be restored to its proper form,
except by months of careful attention and slight over-lowering at each
shoeing. The diagrams (Figs. 25 and 26) represent vertical sections
through a foot from side to side. One shows the wall uneven at the
base, the other shows it uneven at the coronet.
[Illustration: Fig. 25.--Uneven at ground surface.]
[Illustration: Fig. 26.--Uneven at coronet.]
Peculiarities in the formation of a limb sometimes cause an apparent
error in the relative position of the foot. Thus we have horses that
turn their toes in, and those that turn their toes out. The cause of
this twist takes place at the upper part of the limb, and it will be
found that when the toes turn out the elbow turns in and _vice versâ_.
The farrier can do no good to this formation, and attempts to alter
it or disguise it by devices in shoeing are only injurious to the
foot,--little deceptions worthy of a horse-coper.
=A good bearing surface= is the primary object aimed at in preparing
the foot for a shoe. The relative position of the limb to the foot
and the proper proportions of every part of the foot are matters to
be borne in mind whilst the farrier is directly forming the bearing
surface for a shoe. A good bearing surface must be even, level, on
sound horn, and as wide as can be obtained to give stability to the
shoe. It should not be limited to the wall. If, without over-reduction,
the use of the rasp leaves a firm portion of the sole as a level
surface continuous with the lower edge of the wall, the best of bearing
surfaces is obtained. (Fig. 27). The bearing surface should be level
from heel to toe, and no part of it can be singled out either as unfit
to bear weight or as specially capable of enduring undue pressure. No
broken or diseased horn should be used as bearing surface for a shoe.
The broken horn should be removed and the diseased horn must, if not
entirely removed, have so much of its border cut or rasped off as will
prevent contact with a shoe.
[Illustration: Fig. 27.]
After forming a level bearing surface with the rasp the sharp outer
border of the wall is lightly removed with the file, so as to prevent
splitting of the horn. The outer surface of the wall should not be
rasped for it affords protection to the deeper layer of horn. The
harder the outer layer of horn is kept the tougher and firmer is the
whole thickness.
=The Sole and Frog= require very little attention. No sensible farrier
now puts himself to the unnecessary trouble of cutting away horn
that is wanted for protection. It was not the practical farrier that
introduced the stupid "paring and cutting" that ruined horses' feet for
nearly a century. It was the theorists, who taught expansion of the
wall and descent of the sole as primary necessities in the function of
a foot, who must be credited with all the evils resulting from robbing
the sole and frog of horn. When a horse is shod with an iron shoe the
wall cannot wear, and therefore it has to be artificially reduced at
each shoeing. But the shoe does not interfere with the wear of a frog,
and the farrier may safely leave that organ entirely to take care of
itself. To some extent the shoe does interfere with the natural wear of
the sole, and, therefore, any flakes of horn which have been prevented
by the shoe from detaching themselves from the sole may be removed.
The best way to remove these is with the buffer. The sole should not
be pared out. I mean not only that the horn should be left strong,
it should not be pared with a drawing knife, even if only a harmless
surface layer be removed. The effect of leaving the sole of a shod foot
with a smooth, level, pared surface is to stop its natural method of
throwing off more or less broken flakes, and to cause it to retain that
which is half loose until it is removed in one great cake.
A portion of the sole that requires a little special care in preparing
for shoeing is the angle between the wall and the bars--the well-known
seat of "corn." This must not be left so as to come in contact with
the shoe. It is not to be "scooped" out, but it should be reduced
distinctly below the level of the wall so that when the shoe has been
in position for a week or two there is still no contact between the
horn of the soles and the iron at that point.
=Level or adjusted surface?= The bearing surface of a hoof must, of
course, be exactly adapted to the surface of shoe intended to be
applied. Presuming that the best surface for a shoe is one level from
toe to heel, I have insisted upon the necessity of a level bearing
surface on the foot. There are, however, exceptional cases in which a
level shoe is not used, and then we must alter the foot accordingly.
Horses that wear the toe of a shoe out of all proportion to the rest
of the iron may be beneficially shod with a shoe turned up at the toe.
To fit such a shoe the hoof surface must not be made level, it must be
rasped away at the toe and rounded off to follow the line of the shoe.
In the three diagrams (Fig. 28) is shown--(_a_) side view of a foot
prepared to suit the turned-up shoe at the toe, (_b_) a level line to
fit a level shoe and, (_c_) a form often adopted on the Continent to
suit a shoe fitted with a slight curve throughout. This adjusted shoe
is designed to imitate the shape of the worn surface of an old shoe
or to some extent the worn surface of an unshod foot. Every farrier
knows how many horses go better after a level shoe has been worn a few
days than when first applied, and it is argued, with reason, that the
greater ease is due to the shoe being worn to the form offering least
resistance to the movement of the foot in locomotion. I have nothing to
say against this form of shoe and the necessary form of foot surface
for it, except that it is more difficult to make than the ordinary
level one. When adopted the curve of the foot should not be obtained by
over-lowering the toe and heels but by leaving the quarters higher.
[Illustration: Fig. 28.--Three forms of bearing-surface.]
FAULTS TO BE AVOIDED.
Fig. 29 shows a hoof in which shortening of the toe has been effected
not by reducing the ground surface of the wall, but by rasping away the
wall in front of the toe. This should not be done with any good foot,
but it may be adopted with feet having an unnaturally long toe and no
superfluous horn on the under surface. A "stumped-up" toe is very ugly
and it weakens the hoof in front.
[Illustration: Fig. 29.--A "stumped-up" toe.]
=Uneven bearing surfaces= are easily produced by a careless use of the
rasp. One side of the wall may be made lower than the other, one heel
may be reduced more than the rest of the foot, or one side of the toe
may be unevenly reduced. In Fig. 30 the foot presents an uneven surface
which not uncommonly results from careless work. The parts over-reduced
are those most easily reached with a rasp. The near foot suffers at
the outside heel and inside toe. The off foot at the inside heel and
outside toe. A left handed farrier would injure the feet in just the
opposite positions.
[Illustration: Fig. 30.--Uneven surface.]
Another fault results from holding the rasp untruly. If we suppose the
inside heel of the near foot to be under preparation and the farrier
inclines his rasp too much inwards, he leaves the wall at the heel
lower than the sole within it. On such a foot a level shoe rests upon
the sole instead of upon the wall, and a bruised heel soon follows.
=Paring away the sole= to produce a deep concave appearance has another
evil effect in addition to that before pointed out. It removes the horn
just within the border of the wall, taking away the natural support,
and leaving as bearing surface for a shoe a narrow ridge instead
of a strong flat surface. Fig. 31 shows this fault, and it must be
remembered that this ridge may be left as thin as a knife edge. Such a
ridge cannot sustain the weight of the horse, and when it yields the
shoe also yields, the clenches are raised and the shoe becomes loose.
[Illustration: Fig. 31.--A Pared-out Sole.]
=Excessive rasping of Wall.= The best farriers--those most proud of
their work--have a great temptation to use a rasp too freely to the
outer surface of the wall. The hoof gets rough, or it may be ridged,
its appearance is improved by being made smooth, and it is only human
to turn out work which is clean and neat. Owners and grooms are rather
inclined to forget the claims of the horse when judging shoeing,
and the result is that some harm is done by excessive rasping. A
strong foot does not suffer much, but its strength is preserved by
leaving the hard outer surface intact. Rasping off an outer layer of
horn favours evaporation and hardening of the underneath layer, and
the toughness so desirable is to some degree replaced by hardness
and brittleness. Excessive rasping below the clenches is even more
injurious than rasping above them. The wall, between its bearing
surface and the clenches, has to withstand the contact of the shoe, and
the perforation by nails. It should be the toughest and strongest part,
and, therefore, should not be rasped more than is necessary to lay down
the clenches and finish the fitting. Unfortunately the neatest work
is done by fitting a shoe "close" and then rasping off any protruding
horn. This is bad for the foot, as it weakens the wall and spoils the
bearing surface at each shoeing. The worst offenders in this direction
are dealers, who sacrifice everything to appearances and insist upon
shoeing being neat at all hazards.
=Opening the Heels= is one of the gravest faults a farrier can be
guilty of. It consists in cutting away the extremity of the wall at
the heel and generally a slice off the side of the frog at the same
time. The effect is to produce an appearance of width at the back of
the foot--to make what is called "a fine open foot." Fig. 31 shows a
foot which has been injured in this way. The wedge shaped opening which
results has many objections. It breaks the continuity of structures
at the heels, it removes horn unnecessarily, it weakens the foot and,
when the wall is interfered with, it shortens the bearing surface for a
shoe. The bearing surface at the back of the foot is perhaps the most
important of any afforded by the wall. The longer the bearing surface
is at the heels the more the base for sustaining weight is brought
under the leg, and the better the position for supporting the body. All
removal of horn that shortens this surface is injurious.
=Over-reduction of hoof= is always a fault. It is true a carefully
fitted shoe on a foot so treated may do no harm for a time. Too much
horn should be left rather than too little. A strong covering of horn
is a protection against many mistakes in the fitting or form of a
shoe applied to a foot. So long as a hoof is everywhere strong enough
to sustain pressure and afford bearing, weight is evenly distributed
throughout the whole foot. When the horn is thin it yields to any
uneven pressure and damage is done to the foot, even if immediate
lameness is not induced.