SHOEING BAD FEET.
Any average farrier can shoe without immediate harm a good well-formed
foot that has a thick covering of horn, but when the horn is deficient
in quantity or quality injury soon takes place if a badly fitted
shoe be applied. There are feet which from disease or accident or
bad shoeing have become, more or less, permanently damaged. Some are
seriously altered in shape. Some are protected only by an unhealthy
horn, and some show definite changes which cause weakness at a special
part. These are the feet which really test the art of the farrier, for
he must know just what to do and what not to do, and must possess the
skill to practice what he knows.
=Flat Feet.= Some horses are born with flat feet, others acquire them
as the result of disease. Too often the flat sole has another defect
accompanying it--low weak heels. Such feet are best shod with a seated
shoe so as to avoid any uneven pressure on the sole, and the shoes
should always be fitted a little longer than the bearing-surface of the
foot, so as to avoid any risk of producing a bruise at the heel--in
other words, of causing a corn. The seated shoe is not advisable on a
hunter. The concave shoe used for hunters has many distinct advantages
and only one disadvantage for a flat foot, viz, that it has a wide flat
foot-surface. It may cause an uneven pressure at the toe on a flat
sole, but this is easily avoided by not making it too wide; perhaps the
very worst thing to do with a flat foot is to try and make it look less
flat by paring it down. The thinner the horn the greater the chance
of injury to the sensitive parts under it, and every injury tends to
make the sole weaker. Leaving the sole strong and thick, whilst fitting
the shoe to avoid uneven pressure, is the principle of shoeing to be
adopted with flat feet.
=Convex Soles.= The sole of the foot should be concave, but as the
result of disease many feet become convex. This bulging or "dropping"
of the sole varies in degree from a little more than flat to an inch or
so below the level of the wall. When the under-surface of a horse's
foot resembles in form the outside of a saucer, fitting a shoe becomes
a work of art. Very often the wall is brittle and broken away and
it is most difficult to find sufficient bearing-surface on the foot
for a shoe. Many of these feet may be safely shod with a narrow shoe
that rests only on the wall and the intermediate horn between the
wall and sole. Such a shoe may, according to the size of the foot, be
five-eighths or even three-quarters of an inch wide. Its thickness
is to be such as will prevent the sole taking any direct bearing on
the ground, and sometimes a shoe of this form is much thicker than
it is wide. The advantage of this shoe is that it is so narrow that
any bearing on the sole is avoided. The disadvantage is that on rough
roads the sole may be bruised by the flint or granite stones. When the
horn of a "dropped" sole is very thin, or when the horse has to work
on roads covered with sharp loose stones, some cover for the sole is
necessary and the narrow shoe is not practicable. To provide cover
for the sole, the web of the shoe has to be wide, and, therefore, the
foot-surface of the shoe must be seated out so as to avoid contact
with the sole. Too often the seating is continued from the inner
to the outer border of a shoe, so that no level bearing-surface is
provided for the wall to rest on. This kind of shoe is like the hollow
of a saucer, and when applied to a foot is certain to cause lameness
soon or later. Each time the horse rests his weight on it the hoof
is compressed by the inclined surface of the shoe, which instead of
providing a firm bearing-surface affords only an ingenious instrument
of torture.
[Illustration: Fig. 80.
Improper bearing surface.
A level bearing surface.]
In even the worst of these deformed feet some good sound horn is to be
found at the heels, where an inch or sometimes two can be utilised for
level bearing. No matter how much seating is required at the toe and
quarters, the heel of the shoe may always be made level.
It cannot be too strongly urged that in the preparation of feet with
bulging soles no horn is to be removed from the sole. The toe is to be
shortened, the heels lowered proportionately, and the bearing-surface
of the wall made level with a rasp. At no place must the shoe rest on
the sole. In nearly every case the toe is left too long and the bearing
taken upon it by the shoe only increases the deformity. In many feet a
large slice might be sawn off the toe with advantage, as the sensitive
foot is separated from the wall by a mass of diseased horn which
presses the wall at the toe forward. (Fig. 81).
[Illustration: Fig 81.
Deformity resulting from Laminitis.
Section showing how front of wall is separated from sensitive laminæ.]
=Sandcracks.= This is the name given to cracks in the wall which
commence at the coronet and extend downwards. From their position
at the toe, or at the side of the hoof, they are sometimes called
respectively "toe-cracks" and "quarter-cracks." The crack may be very
slight and may exist without causing lameness. It may appear suddenly,
accompanied by great lameness and by the issue of blood from between
the edges of the divided wall. These are grave cases which require
surgical attendance. Sandcracks are most commonly seen in dry brittle
feet, and the horses most subject to them are those employed in heavy
draught work. Railway shunt-horses and omnibus horses are very liable
to be troubled with sandcracks in the toe of the hind feet.
In shoeing for this defect there are two things to avoid, (_a_) not to
place any direct pressure on the part; (_b_) not to fit a shoe which
will tend to force the crack open. Following these lines it is well
not to put a clip exactly over a crack. If at the toe place a clip
each side of the crack, and never use calkins or high heels which
throw the weight forward. If at the quarter avoid a spring-heeled shoe
which permits the downward movement of the foot behind the crack and
so forces it open. In all cases, after fitting the shoe level to the
foot, remove a little more horn just below the crack so as to relieve
the direct bearing on the part. (Fig. 82).
[Illustration: Fig. 82.
=A=--Horn removed to prevent pressure.
Bearing relieved at wrong place by "springing" the heel.]
In the case of crack extending the whole space of the wall some
provision should always be made to keep it from opening, because every
step of the horse, especially when drawing a load, causes an outward
pressure at the coronet. This pressure forces the hoof apart and the
injury caused does not cease with the pain and lameness which follow,
and which may be temporary. Doubtless the original cause of a sandcrack
is some morbid condition of the coronary band--the band from which the
wall grows. The sensitive laminæ are at first not affected further than
by the inflammation consequent upon the direct tearing which occurs
when the crack takes place. The continued irritation, kept up by a
persistent fissure in the horn covering the laminæ, soon causes other
serious changes which tend to make the sandcrack a permanent disease.
Thus even the smallest crack should be attended to and measures adopted
to prevent its enlargement or, when extensive, to limit all opening and
shutting movement of the hoof.
[Illustration: Fig. 83.--French Clips in Position.]
This is sometimes attempted by a simple leather strap tightly applied,
or by binding the foot with string or tape. Tape is less liable to
slip than string. When the hoof is sufficiently thick two nails may
be driven in opposite directions transversely through the crack and
clinched; or French sandcrack-clips (Fig. 83) may be used which are
easily applied. The instruments necessary are shown below (Fig. 84).
The iron (_b_) is made red-hot and pressed on the hoof over the crack
so as to burn a groove each side of it. Into these grooves the clip
(_a_) is put and the pincers (_c_) are then used to compress the clip
firmly into its place. There is a strain upon the clips, and sometimes
one breaks. It is therefore necessary always to use two, and for an
extensive crack three may be employed.
[Illustration: Fig. 84.]
All these appliances tend to keep the lips of the crack from
separating, but they do not prevent the edges of a deep wide crack from
being forced together and thus pinching the sensitive parts. To provide
against this injury a slip of hard wood may be fitted into the crack,
and then the nails or clips may be more safely drawn tight without fear
of injury, and with a better chance of preventing any movement in the
edges of the crack. To insert the wood, the crack is converted into a
groove nearly as deep as the wall, about three-eights of an inch wide,
with straight sides, or better still, with a little greater width at
the bottom than at the surface. Into such a groove a piece of wood
formed to fit it is gently driven from below and rasped off to fit
exactly. Or, softened gutta-percha may be pressed firmly into the space
and levelled off when cold.
To "cut out" a sandcrack except for the purpose of refilling it is bad
practice as it favours movement and helps to make the defect permanent.
To rasp away the horn so that only a thin layer is left is also
injurious. No horn should be removed except for the fitting of a plug
as above described or, under veterinary direction, for the purpose of
giving vent to matter which has formed within the hoof.
In many European countries a shoe is used for toe-cracks which has two
clips drawn on the inside border of the shoe at the heels. These clips
catch the bars of the hoof and prevent the heels of the foot closing
in. The idea is that when the wall at the heels contracts, there is a
tendency for the wall at the toe, if separated by a crack, to open.
Fig. 85 shows the position of the clips which must be carefully fitted
so as to rest on the inside of the bars. Mr. Willis, V.S., has tried
these shoes and speaks well of their utility.
[Illustration: Fig. 85.--Shoe with Heel Clips for Sandcrack.]
When the crack is in the quarters of the foot, it is not the tendency
to expansion of the hoof that has to be guarded against. It is the
downward motion of the heels that forces open a crack in this position.
The farrier provides against this by taking care to have a firm bearing
of the shoe on the hoof behind the crack as shown in A figure 82.
=Contracted Feet.= Some diseases of the foot lead to contraction of
the hoof, which is most noticeable round the coronet and at the heels.
Any long continued lameness which prevents the horse placing the usual
weight on the foot may be accompanied by contraction. Constant cutting
away of the bars and paring the frog so that it takes no contact with
the ground also leads to shrinking in of the heels. By lowering the
heels and letting the frog alone many feet will in time widen out to
their proper size, but no system of shoeing is so good for contracted
feet as the use of tips, which leave the whole back part of the hoof to
take direct bearing on the ground.
Many shoes have been invented for forcing open the heels of contracted
feet. Some have had a hinge at the toe and a movable screw at the
heel. Some have had the bearing-surface at the heels made with a slope
outwards, (See Fig. 53, page 74) so that the weight of the horse should
constantly tend to force the heels apart. There is no necessity for any
of these contrivances. A properly fitted tip (See page 78) will permit
the hoof gradually to expand to its healthy size and form.
=Seedy-toe.= This is a condition of the wall usually found at the toe
but not uncommon at the quarters. It is not common in hind feet but
occurs sometimes. When the shoe is removed a separation is noticed
between the sole and the wall, and this separation may extend up the
wall nearly to the coronet. As a rule the space so formed is a narrow
one, but it may be wide enough to admit three fingers of a man's hand.
Probably all seedy toes result from some injury or disease of the
coronary band from which the wall grows, and the first appearance is
not a cavity but a changed and softened horn, which may be dry and
crumbly, or moist and cheesy. The diseased horn may be scraped out
and the cavity filled with tar and tow. The wall bounding the cavity
should be relieved of all pressure on the shoe, and if a radical cure
be desired all the unattached wall should be cut away. This, however,
should be done under veterinary guidance.
=Turning in of the Wall.= By this expression, I mean those cases of
weak low-heels in which the border of the wall turns inward. Such a
form of horn offers no suitable bearing for a shoe, and if submitted to
pressure by a shoe gets worse. Too often this condition is treated by
paring away the sole within, which increases the deformity. The sole
should not be cut but be left as strong as possible. The curled-in
border of the wall should be cut down and all bearing taken off the
shoe. In one or two shoeings the wall will resume its proper form. When
both heels are so affected, and the horse has to remain at work, only
one heel must be treated at a time. The extreme point of the heel is
never affected, and affords a point for bearing when the border of wall
in front of it is cut away so as not to touch the shoe.