I have a quarter horse who presented early onset ringbone in the right hind at about 18 months. Causal factors can include sepsis and trauma to the bone periosteum. This particular horse was worth a small fortune so surgery was performed to mechanically fuse the pastern joint. The horse went on to a moderately successful show career at the congress level. He's now 13 years old and still getting around. I keep this horse shod all around to provide the support and medial/lateral mechanics that facilitate both his comfort and performance level. So far, so good.