A Text-Book of Horseshoeing, for Horseshoers and Veterinarians

by A. Lungwitz

As long as the bones, articulations, muscles, and tendons of the limbs remain healthy, just so long will the legs maintain their natural direction and position. Frequently, however, this normal condition of the limbs is gradually altered by disease of the bones, joints, and tendons, and defects in the form and action of the lower parts of the limbs arise that often require attention in shoeing.

THE FOOT.

A. The Bones of the Foot.

Since the horse is useful to man only by reason of his movements, his foot deserves the most careful attention. The horseshoer should be familiar with all its parts. [Fig. 3] shows the osseous framework of the foot, consisting of the lower end of the cannon bone (A), the long pastern (B), the two sesamoid bones (C), the short pastern (D), and the pedal bone (E). The lower end of the cannon, or large metacarpal bone (A) exhibits two convex articular surfaces (condyles) separated by a median ridge running from before to behind, and all covered by articular cartilage. On both the external and the internal aspects of the lower end of the cannon are small uneven depressions in which ligaments take their attachment.

Fig. 3.

The condyles of the cannon articulate with the os suffraginis (long pastern) and the two sesamoids ([Figs. 3, C], and [4, B]) in such a manner that in the forefeet the cannon makes an angle with the long pastern of from one hundred and thirty-five to one hundred and forty degrees, and in the hind feet of from one hundred and forty to one hundred and forty-five degrees.

The long pastern (first phalanx) ([Fig. 4, A]) is about one-third the length of the cannon; its upper and thicker end presents two condyloid cavities (a) (glenoid cavities), separated by a median groove, which exactly fit the condyles and ridge at the lower end of the cannon. The lower end of the long pastern is smaller than the upper, and is provided with two condyles, between which is a shallow groove (e). The anterior face of the bone is smooth, rounded from side to side, and blends into the lateral borders. The posterior face is flatter, and shows a clearly marked triangle to which ligaments attach.

The two sesamoid bones ([Fig. 4, B]) are small, and somewhat pyramidal in shape, and, lying against the posterior part of the condyles of the cannon bone, increase the articular surfaces at the upper end of the long pastern.

Fig. 4.