Inside the hoof

A living structure

The British Horse Society describes the hoof as "more than just a hard shell": it is a complex, living structure in which each part has a specific job, from bearing weight to helping circulation. Knowing the parts helps you spot problems early and talk to your farrier and vet.

The outside of the hoof

Hoof wall. The hard outer layer that protects everything inside. It is made of keratin, the same material as human hair and nails, and it carries most of the horse's weight. The wall grows slowly down from the coronary band to the toe, taking about 9–12 months to grow all the way down. A healthy wall looks smooth, without cracks, lumps or lines, and may be one colour or striped.

Coronary band. The strip at the top of the hoof where the skin meets the wall. It produces new hoof and supplies the wall with nutrients, so damage here can affect how the hoof grows.

Heel bulbs. The rounded, soft parts at the back of the hoof. They let the hoof expand and contract as the horse moves, which absorbs impact and keeps the foot stable on uneven ground.

Underneath the hoof

Pick up a foot and you will see:

• The sole. The underside of the hoof, slightly concave to absorb shock and protect the inside of the foot. It is firm but flexible, and it isn't designed to carry the horse's full weight; the wall does that.
• The frog. The soft, V-shaped structure in the middle of the underside. It absorbs shock and pushes blood back up the leg when the horse moves, which is important for circulation and for the hoof's flexibility.
• The white line. Where the wall meets the sole. It holds the hoof together and keeps out dirt and germs, and problems can start if it becomes weak or stretched.

The British Horse Society's riding-award guidance also names the bars, the point and cleft of the frog and the seat of corn as parts of the foot a rider should be able to identify.

Inside the hoof

Pedal bone. The main bone inside the hoof, also called the coffin bone. Its strong, slightly curved shape fits the hoof and spreads the horse's weight evenly, and tendons and ligaments attach to it. Its position and health are vital for balance and soundness.

Laminae. Thin, leaf-like layers that attach the hoof wall to the pedal bone like strong hooks. There are two types: sensitive laminae, which have a blood supply, and insensitive laminae, which are part of the wall. Together they hold the pedal bone in place while the wall grows past it.

Digital cushion. A thick, soft pad under the pedal bone and behind the frog. It acts as a shock absorber and helps pump blood back up the leg.

Collateral cartilages. Two pieces of cartilage, one on each side of the hoof near the heel. They help the hoof expand and contract, making it more flexible, and protect the joints inside.

Navicular bone. A small bone behind the pedal bone, held in place by strong ligaments. A fluid-filled sac, the navicular bursa, lets the deep digital flexor tendon slide smoothly over it. The navicular bone and bursa are part of the coffin joint, between the pedal bone and the short pastern bone, which plays a key role in movement and weight-bearing.

Why a horse has one toe

Modern horses, asses and zebras walk on a single toe on each foot: the original third toe, encased in a thick-walled keratin hoof with a triangular frog underneath that acts as a shock absorber. Their distant ancestors were very different. Researchers at the University of Bristol describe early horses such as the Eocene Hyracotherium as having feet like a modern tapir's: four toes in front and three behind, each with its own small hoof and a foot pad.

What happened to the other toes? In 2023, a team including University of Bristol palaeobiologists confirmed that they have been lost completely in evolution, not hidden inside the hoof as a 2018 paper had proposed. The upper parts of the side toes survive as the splint bones, fused alongside the cannon bone, but the toes themselves are gone. The frog evolved separately, as a structure of its own that provides shock absorption and grip.

An earlier Bristol study argues that the key step in horse foot evolution was not losing toes but the "spring foot". This pogo-stick-like foot stores elastic energy in the tendons of the leg as the horse moves. It evolved in three-toed ancestors as grasslands spread across North America around 20 million years ago. Single-toed horses appeared in North America around 12 million years ago. The researchers propose that a single toe suited energy-efficient trotting while roaming for food and water, rather than galloping away from predators: in their words, the foot was important "for finding food, rather than for avoiding becoming food themselves".

Looking after the hoof

Pick out and check your horse's feet as part of the routine in the daily care guide. Your farrier will advise on trimming and shoeing for your horse.