Stocking up, also known as Filling up or Filled legs refers to a condition in horses caused when fluid builds up and swells the leg. Sometimes it is linked to lameness and other times it is purely an aesthetic problem. Fluid buildup can be caused by dozens of different things, though often is seen in horse standing in a stable or horse trailer for long periods of time. Standing after inadequate cool down following hard exercise is a common source of filling up
Filled legs with no injury or lameness may go down with light exercise. Bandaging with a stable bandage or "standing wrap" can help prevent and reduce the swelling.