The small bone in the foot of the horse is called the navicular bone. It is a part of the bony skeleton of the leg, sitting at the posterior aspect of the joint where the third phalanx bone articulates with the second phalanx bone.

The third phalanx is often called the coffin bone in the horse because it is encased in the hoof. The second phalanx is often called the short pastern bone.

The navicular bone is held in place by ligaments which arise from the dense connective tissue of the bone surface and stretch to the adjacent bones. Along the posterior aspect of the navicular bone and curling underneath it, the deep digital flexor tendon stretches to attach firmly to the under surface of the coffin bone.

Navicular Disease is a soundness problem in horses, and not an actual disease. Thus, the correct term is navicular syndrome as opposed to disease.

Recently much of the original literature concerning navicular disease has been called into question, particularly the significance of some radiographic changes.

It is okay if you are not familiar with the term navicular syndrome, even veterinarians don’t agree as to what it really is. They prefer to call it navicular syndrome than navicular disesase. This signifies that a variety of problems can cause the disease.

It is not always possible to pinpoint the exact cause of the navicular syndrome. Because there are a variety of causes, not one treatment is successful.