The most common joints affected are the fetlock, the hock and the carpus. Angular limb deformities can be congenital or acquired. Congenital means the foal is born with the condition. At the time of birth, or within a few hours, the owner can see a turning in or out of the leg. When ALD is acquired, the foal was normal at birth, but something has happened to cause the limbs to grow at an angle.
Surgery is one treatment option.
The procedure used most often is called periosteal stripping. It is thought that the combination of physically releasing the pressure on the growth plate and interrupting the blood supply to the bone have the desired effect of allowing the bone to grow faster on one side, thus straightening the limb. Another surgical procedure is trans-physeal bridging. Orthopedic screws and wire are placed in or around the growth plate to slow bone growth on one side, thus allowing the limb to straighten. Periosteal stripping is often done in conjunction with this procedure.