Sesamoiditis

Location of the sesamoid bones, behind the fetlock.

Sesamoiditis is inflammation of the sesamoid bones in the horse's fetlock. The sesamoid bones lie behind the bones of the fetlock, at the back of the joint, and helps to keep the tendons and ligaments that run between them correctly functioning.

Usually periostitis (new bone growth) occurs along with sesamoiditis, and the suspensory ligament may also be affected. Sesamoiditis results in inflammation, pain, and eventually bone growth.

Causes

Sesamoiditis is generally caused by excess stress on the fetlock joint. Conformation that promotes sesamoiditis include long pasterns or horses with long toes and low heels.