When the grooving is in a horizontal direction, a single incision is sufficient.  This is made 3/4 inch below the coronary margin of the wall, and parallel with it, extending from the point of the heel for 2 or 3 inches in a forward direction.  As in the previous method, a bar shoe is applied, and the animal daily exercised.  Thus separated from the fixed and contracted portion of the wall below, the more elastic coronet under pressure of the body-weight commences to bulge.  The bulging is of such an extent as to cause the new growing hoof from the top to considerably overhang the contracted portion below, and cure of the condition results from the newly-expanded wall above growing down in a normal direction.

This consideration of contracted heels may be concluded by drawing attention to the advisability of always maintaining the horn of the wall in as soft and supple a condition as is natural by the application of suitable hoof dressings.

A useful one for the purpose is that made with lard, to which has been added a small quantity of wax or turpentine.

Especially should a dressing like this be used when the hoof is inclined to be hard and brittle, and where tendency to contraction has already been noticed.

The application of a hoof ointment is also particularly indicated where the foot is much exposed to dampness, where the animal is compelled to stand for long periods upon a dry bedding, or where the bedding is of a substance calculated to have a deleterious effect upon the horn.

This, in conjunction with correct shoeing, will probably serve to avoid the necessity for more drastic measures at a later time.

(b) LOCAL OR CORONARY CONTRACTION.

Definition.—­Contraction at the heels, confined to the horn immediately succeeding that occupied by the coronary cushion.  Really, the condition is but a somewhat arbitrary subdivision of contracted hoof, as we have just described it in general.  For that reason we shall give it but very brief mention.

Symptoms.—­In this case the horn of the heels, instead of running down in a straight line from the coronary margin to the bearing surface of the wall, presents a more or less distinct concavity (See Fig. 79, a, a).

As is the case with contraction considered as a whole, this deformity may affect one or both heels; and during its first appearance, which is after the first few shoeings, the animal may go distinctly lame.

Causes.—­Coronary contraction may occur in hoofs of normal shape immediately shoeing is commenced, and frog pressure with the ground removed.  It is far more likely to ensue, however, if the hoof is flat, with the heels low, and the wall sloping.  And with those predisposing circumstances it is that the horse goes lame, and not with the hoof of normal shape.

Seeing, then, that this condition is largely dependent upon the shape of the foot, we may, to some extent, regard it as hereditary.  Seeing further, however, that it only appears when shoeing is commenced, we may in a greater degree also regard it as acquired.  The lesson, therefore, that this and other forms of contraction should teach us is the carefulness with which the shoeing should be superintended in a large stud, or in any case where the animal is of more than ordinary value.