Mark, in your experience, what "causes" flat soles? Is it an underlying conformational thing, having to do with--I don't know--the alignment of the coffin bone or something? Or is it more of a genetic predisposition to growing a "bad foot." And if it's the latter, why can't you fix the problem with corrective trimming, hoof supplements, and dressings like Keratex for sole thinness?
I'm not Mark, but those barefoot hoof pics are my horse. Since I have a 21 year history with him, I can say:
He was like that when I bought him as a coming three year old.
He is a registered Tennessee Walker who didn't "Make" for the Performance world and went to auction at 18 months of age. It is safe to say that, at his young age, he was never subjected to stacks but most likely did have some sort of weighted shoe on him during his 30 days of training.
He's been a trail horse the entire time I have owned him and I don't mean those quiet little hacks in a Metro Park. He always wore shoes during riding season and barefoot in the winter. I rode him barefoot thru the winter without issue but that was because we had miles of old abandoned railroad beds and the edges of the neighbors' hay fields to use.
He was formally diagnosed with Equine Metabolic Syndrome in May, 2007<---that is almost the same as insulin resistance but not quite. He suffers some muscle wasting, which is not typical with IR.
So far <knock-on-wood> he has never in his life had a laminitic episode or any abscesses due to being flat-footed and/or suffering from EMS.
His hooves are stronger now, he will be 24 in October, than they have ever been. Much of that due to his strict diet (I didn't know as much about diet after all, as I thought I did), and frequent trims.
If your intended use exceeds the animals ability to perform
is really the bottom line