A hoof of the base-narrow position is normally wry, but never so pronounced as a hoof of the base-wide position. The inner wall is but little, more oblique than the outer, the difference being most noticeable at the quarters ([Figs. 65] and [66]). The curve of the plantar border of the wall is similar to that of a regular hoof, except that the inner side wall and quarter are a little more sharply curved in a base-narrow hoof. Occasionally the outer quarter is somewhat drawn in under the foot.
This form of hoof is most distinctly marked in animals that stand toe-narrow or are bandy-legged.
As to the forms of the hind hoofs, what has been said concerning the influence of position of the limbs upon the shape of the front feet will apply equally well to them. The hind hoof ([Fig. 82]) is not round at the toe, but somewhat pointed or oval. It greatest width is between the middle and posterior thirds of the sole. It usually has a strongly concave sole and a somewhat steeper toe than the fore-hoof; viewed from the side, the angle of the toe with the ground in the regular standing position is from fifty to fifty-five degrees.
Fig. 82.
Right hind hoof of the regular position: a, side wall; b, beginning of the quarter; c, beginning of the bar; d, buttress; e, middle of bar; f, body of the sole; f′, branch of sole; g, white line of the toe; g′, white line of the bar; h, body of the frog; i, branch of the frog; k, bulbs of heel; l, middle cleft of frog; m, lateral cleft of frog.
Finally, we also distinguish wide and narrow hoofs; they are not dependent upon the position of the limbs, but upon the race and breeding of the animal.
The wide hoof ([Fig. 83]) is almost round upon its plantar surface. Its wall runs quite oblique to the ground. The sole is but moderately concave, and the frog is strong and well developed. The narrow hoof ([Fig. 84]) is rather elliptical, with steep side walls, strongly concaved sole, and small, undeveloped frog. The horn of the narrow hoof is fine and tough; of the wide hoof, usually coarse. The wide hoof may readily become flat. Narrow hoofs are either the result of breeding or premature shoeing.
In enumerating the preceding forms of the hoof we have by no means referred to all the forms in which the hoof may be found; on the contrary, hoofs vary in shape and quality to such an extent that among a hundred horses no two hoofs can be found which are exactly alike. In fact, the same variety exists as in the faces of people, and we know that we can recall in succession even many more faces without finding two that are exactly alike. This explains the manifold differences in horse’s shoes with respect to size, form and other qualities.
Fig. 83.