The fetlocks of a horse are its lower joints, which can be seen when it’s standing. When the fetlocks drop below the level of the cannon bones and hocks while the horse is standing, this is known as a dropped or low-set fetlock. This condition can be caused by several different factors, including joint laxity due to genetics or poor conformation; trauma to the area such as an injury or strain; long periods of inactivity that cause muscles to weaken; and certain diseases like osteochondrosis (OCD) or chronic synovitis. Treatment for dropped fetlocks typically involves corrective shoeing and exercise, but in some cases surgery may also be necessary.