A
horse hoof is a structure surrounding the distal
phalanx of the 3rd digit (digit III of the basic
pentadactyl limb of
vertebrates, evolved into a single weight-bearing digit in equids) of each of the four limbs of
Equus species, which is covered by complex soft tissue and
keratinised (cornified) structures. Since a single digit must bear the full proportion of the animal's weight that is borne by that limb, the hoof is of vital importance to the horse. The phrase "no hoof, no horse" underlines how much the health and the strength of the hoof is crucial for horse soundness.