Bruises to a horse's hoof wall, sole, frog or heel are a very common cause of foot lameness. They are usually caused by blunt trauma, such as impact from a stone.

However, bruising can result from pressure on the sole from an improperly placed or twisted shoe or pad, packed snow or dirt, over-trimming. Horses with pigeon-toes, overgrown heels, and flat feet are thought to be more predisposed to developing heel bruises.

Corns are a type of bruise that occur in the angle of the sole, between the hoof wall and bar of the hoof. Corns usually develop on the front feet, and are thought to result from improper shoeing or work on hard surfaces. Sometimes, there will be swelling of the pastern and fetlock from inflammation ascending up the limb from the bruise.

These bruises can be very painful. Trauma causes internal bleeding within the foot that result in a hematoma, a pressurized swelling of blood.

If the injury is near the surface of a non-pigmented or white hoof wall, you may see blood underneath or a subtle discoloration of the sole or heel area. If the injury is deeper you may not see any sign of injury, but the internal damage may be severe. Left unattended, sole bruises can cause chronic inflammation and result in pedal osteitis.

This injury is commonly diagnosed by vets with hoof tester application. A palmar digital nerve block confirms that the problem is in the foot, and negative radiographic findings also make this diagnosis more likely.

However, this diagnosis can be easily confused with laminitis and other foot injuries, which can be very costly if missed.