Chronic Suspensory Ligament Desmitis

Have you ever seen an old horse with it's hind fetlocks dropping down close to the ground? Well if you have, this is what's going on inside the leg. Inside the box is the branch of the suspensory ligament where it attaches to the sesamoid bone. The red area of the ligament is showing how inflammed it is and the attachement to the bone is almost gone. The function of the suspensory ligament is to "suspend" the fetlock up off the ground. When the ligament breaks down, the fetlock drops.
Inside the circle is fibrous tissue that develops secondary to the suspensory ligament breakdown. These horses are very painful and have difficulty moving around.