Yeah Nutty, I was just pointing out that I don't think it *wears* away. More like eaten away, in conjunction with bad mechanics causing leverage. Would be interested to see some recent pics of that horse's feet??
Elbandita, you're talking of the above pic? Some similarities with OP(tho obviously pony not half that bad) & yes, I'm confident to say that there is definitely WLD present in both, which is exacerbating the problems. Separation doesn't generally *cause* WLD though IMO, but WLD commonly causes separation. WLD/Seedy toe is an opportunistic infection that can get into unhealthy/compromised hoof tissue. It can be bacterial, fungal or otherwise.