[Illustration:  FIG. 84.—­THE SHOE WITH EXTENDED TOE-PIECE AND HIGH CALKINS.]

With this shoe a certain amount of forced exercise is advisable, and at intervals of about two weeks the calkins should be somewhat lowered, until the heels are brought as close to the ground as is possible.  In giving directions for this shoe to be made the veterinary surgeon must, when referring to the length of the toe-piece, be guided entirely by the condition of the case.  Ordinarily, a suitable length is from 3 to 4 inches.  It is necessary also to warn the owner that, by reason of the length projecting, the shoe is liable to be torn off.

Should the ‘knuckling over’ have become complicated by bony deposits round the seat of the original injury, then a favourable modification of the condition is not so likely to result.

The benefit to be derived from the shoe with an extended toe-piece in a case of excessive knuckling is admirably shown in a brief report of a case, under the title of ‘Hooked Foot,’ in vol. xiv. of the Veterinary Record, p. 716: 

‘An eighteen months’ old filly showed a deformity of the third phalanx, resulting in her walking with the front face of the hoof on the ground.  The flexors were apparently all right, and the bending back seemed to be due to contraction of the ligaments of the joint and the sheath of the perforans.

’On the ground of absence of contraction of the flexors, or atrophy and paralysis of the extensors, the surgeon considered the lesion curable by simple orthopaedic measures.  By means of an elongated toe-piece to the shoe and calkins, which were shortened every fifteen days, the filly was completely cured in seventy days.’

H. THE CROOKED FOOT.

(a) THE FOOT WITH UNEQUAL SIDES.

Definition.—­The foot thus affected has one side of the wall higher than the other.

Symptoms.—­This deformity is the better recognised when the foot on the floor is viewed from behind.  In addition to the difference between the height of the inner and outer heel is seen at once a deviation in the normal direction of the horn.  That of the higher side is distinctly more upright than that of the lower, and runs from above downwards and inwards towards the axis of the foot, while the horn of the lower side maintains its normal direction of downwards and outwards.

From what we have said before on contracted foot, this bending in of the wall of the upright side will at once be recognised as a form of contraction.  It is, in fact, contraction confined to one-half of the foot only, and, as a result, the upright side of the crooked foot is prone to the troubles arising from that condition.  Corns are frequent, and atrophy of that half of the frog on the affected side supervenes.  With the inflammatory changes accompanying these conditions we find the horn of the affected side deteriorating in quality.  It becomes dry and brittle, and extremely liable to sand-crack.  At the same time, thrush of the contracted frog begins to make its appearance.