Causes.—­More often than not this condition is a result of the conformation of the limb.  According as the build above inclines the animal to ‘turned in’ or ‘turned out’ toes, so shall we have feet with a wall crooked inwards or crooked outwards; and it may be mentioned here that the evil results inflicted on the foot by ill-shaped limbs above will make themselves the more readily noticed when the animal comes to be shod for any length of time.  So long as a natural wear of the foot is allowed, so long does it accommodate itself to the form of limb above.  So soon, however, as the shoe is applied, and a more or less equal (and in this case harmful) wear by that means insisted on, so soon does this abnormal change in the height and direction of the horn fibres begin to make itself seen.

While arising in the majority of instances from faulty conformation of the limb, crooked feet may also be brought about by bad shoeing, or by unequal paring of the foot, and, in a few cases, from unequal wear of the foot in a state of nature.

Treatment.—­Although it may be taken as a rule that lowering of the higher wall, even if persisted in at every shoeing, will do nothing towards remedying the primary cause (viz., the evil conformation of the limb), yet it will serve to keep the condition within reasonable limits.  In this case, while removing so much of the wall as is deemed necessary, care must be taken to leave uncut the sole and the bar.  Leaving these intact gives us two natural and very potent protections against the contraction already mentioned as impending.

Where, by reason of the thinness of the horn or other causes, sufficient paring to equalize the tread cannot be practised, then the same end may be arrived at by the use of special shoes.  That branch of the shoe applied to the half of the foot with the lower wall should be thickened from above downwards.  Or, on the same branch, may be turned up a calkin of sufficient height for the purpose.  Of the two methods the first is preferable.

In any case, whether depending upon paring, or upon the use of a special shoe, the animal should be sent to the forge quite often, for it is only by a well-directed, and therefore constant, application of the principles here laid down that improvement may be brought about.

When marked contraction of one-half of the foot is present, it will be best treated with the expanding shoe of Hartmann, already described in the section of this chapter dealing with contracted heels (see Fig. 76).

(b) THE CURVED HOOF.

Definition.—­The hoof with the wall of one side convex, and that of the opposite side concave.  Fig. 85, showing the foot in section from side to side, gives an exact idea of this malformation.

Causes.—­As was the case with the condition previously described, this abnormality finds its primary cause in an unequal distribution of weight due to vice of conformation in the limb above, causing one side of the hoof to be higher than the other.  As a result of this, the wall that is inordinately increasing in height commences to bulge outwardly (Fig. 85, a), while the opposite (Fig. 85, b) becomes concave.