Symptoms.—­Spongy hoof is quite common in animals that have large, flat, and spreading feet—­in fact, the two appear to run very much together.  It is a common defect in animals reared in marshy districts, and of a heavy, lymphatic type.  The Lincolnshire Shire, for instance, has often feet of this description, and, the causative factors being in this case long-continued, render the feet extremely predisposed to canker.  The horn is distinctly soft to the knife, and has an appearance more or less greasy.  Animals with spongy feet are unfit for long journeys on hard roads.  When compelled to travel thus, the feet become hot and tender, and lameness results.  A mild form of laminitis, extending over a period of three or four days, often follows on this enforced travelling on a hard road, more especially in cases where the animal is ‘heavy topped,’ and the usual food of a highly stimulating nature.  In fact, it has been the author’s experience to meet with this condition several times in the case of shire stallions doing a long walk daily upon hard roads, with the weather hot and dry.

Treatment.—­When a horse with spongy feet is shod for the first time, care must be taken to avoid excessive paring of the sole, for already the natural wear of the foot has been sufficient to keep the soft horn in a state of thinness.  For the same reason hot fitting of the shoe must not be indulged in for too long a time.  That common malpractice of the forge, ‘opening up the heels,’ must, in this case, be especially guarded against, or the excessive paring of the frog and partial removal of the bars that this operation consists in will lay the foot open to risk of contraction.  To begin with, the heels are naturally weak, and, once the bars are removed, there is nothing to prevent them rapidly caving in towards the frog.  Even when carefully shod, a foot of this class is readily prone to contract directly the animal is brought into the stable, and the horn commences to dry to excess.  An ordinary light shoe should be used, and the nails should be light and thin.  They should be driven carefully home, and the ‘clinching’ made as tight and secure as possible.

G. CLUB-FOOT.

Definition.—­Under this name we indicate all cases in which the horn of the wall become straightened from above to below.  It will, therefore, include all conformations varying from the so-called ‘upright hoof,’ in which the toe forms an angle of more than 60 degrees with the ground, to the badly ‘clubbed’ foot, in which the horn at the toe forms a right angle with the ground, or is even directed obliquely backwards and downwards, so that the coronary margin overhangs the solar edge of the wall.

[Illustration:  FIG. 83.—­THE CLUB-FOOT.]