How do hooves protect the feet of horses and other ungulates?

Hooves serve as a vital adaptation for ungulate mammals, providing a strong, insensitive surface that allows these animals to bear their body weight while walking on the tips of their toes.1

Constructed from the fibrous protein keratin, a hoof consists of two primary components that work together to protect the foot:

• Unguis: This hard, upper portion forms a protective covering that surrounds the end of the toe and extends downward to create a durable rim around the bottom.1
• Subunguis: This softer plate covers the bottom of the toe, functioning as a tough pad that cushions the foot.1

For perissodactyls like horses, which walk on the tips of single digits, these structures are highly developed to support speed and endurance. Because the hoof is subject to constant wear, it grows continuously from living cells at its base throughout the animal's life. In domestic horses, horseshoes are often applied to the hard unguis to provide additional protection against splitting or breaking.1