my cousin have a horse she purchased at an auction several weeks ago. the horse has a knot on her left fetlock.it would take both of my hands to go around the knot. the man she purchased it from said it was ok she probaly got kicked or hit it on the gate. the knot is hard like bone and she doesn't react when it is squeezed. the knot appears to be getting bigger and after she is rode she limps. she is also with foal. she is a big momma. do we need to have it x-rayed or wrap it when she is rode or what?