Hoofs

Hoofs are the hard, keratinous coverings that encase the distal digits of many hoofed mammals, collectively known as ungulates. They protect the toe, bear weight, and grow continuously from the coronary band. The outer hoof wall forms the visible covering, while the underside includes the sole and, in some species, a soft, elastic region that aids shock absorption.

There are two main hoof types. In horses and other single-toed ungulates, the entire weight is carried by a single toe with a thick, continuous hoof. In many artiodactyls, including cattle, sheep, goats, and deer, two digits per foot bear weight, each with its own hoof, forming a cloven hoof. Some species have more than two toes per foot; for example, rhinoceroses have three toes per foot, each with a hoof-like covering. Habitat and movement patterns have driven the diversification of hoof structure across different lineages.

Anatomy commonly includes an external hoof wall, a protective sole, and, in horses, a frog—a soft, elastic structure that helps absorb impact and promotes circulation. Hoofs grow continuously and require maintenance through trimming or shoeing, especially in domestic horses, to maintain shape, function, and prevent injury. Hoof health is essential for mobility and can be affected by conditions such as laminitis in horses, hoof rot in livestock, cracks, and abscesses.

Evolution and function: hooves evolved from claws to support rapid locomotion and weight-bearing on diverse terrains. The variety in hoof form reflects ecological niches, locomotor demands, and dietary adaptations across ungulates.