MGM - I think I've seen it in the agri stores, usually the horse section.
OS - I've moved mine to the dairy goat shed at night, the only building with a hard floor but thats old slate pitchings and patches of old concrete, not easy to clean out every day.
I'm using lime, cleaning out, checking and spraying at least twice a week.
They had ab injection last week, I've been spraying with abs and still there's two limping again today.
The dairy goats rarely get problems and they're all together in the same conditions. Angoras just have grotty feet. I've yet to hear from anyone who keeps them and doesn't have problems.