I had excellent results with Focus Hoof from Source. I struggled with my late TB’s hooves from the day I got him in 2005. We tried Farrier’s Formula with meh results early on. We made do for several years, just writing them off as “TB feet, whattya gonna do?”.
Then it hit the fan, that his hooves literally could not hold a nail. The farrier didn’t believe they’d hold up to glue ons, either. He described it as trying to set a nail in wet cardboard. I’d happened to start him on the Focus Hoof as a test to see if the Cu/Zn would help keep his coat from bleaching a couple weeks prior. Well, the fading test went out the window as he spent that summer in during the day and out overnight in boots. He only went out in boots for almost a year while his hooves grew out. I kick myself for not getting before, during, and after pictures as his feet grew out; the difference in the wall quality was night and day. You could see the difference in the horn density as it grew out.
Through all of this, he was getting 4-6 lbs of Triple Crown Senior and usually 1/2-1 lb of a 25% fortified fat supplement, as well as oil and beet pulp over the winter. On paper, he SHOULD have been getting what he needed, but that horse NEVER read the paper. Anyway, I kept him on it for about three years, until money became quite tight and I dropped it. According to the farrier that had worked on him before, during, and after the “wet cardboard” episode, until the day he died that farrier said he had some of the toughest hooves he trimmed (and he stayed comfortably barefoot the last three years of his life, which I never imagined happening).
tl;dr, Source’s Focus Hoof worked wonders for my crappy-hooved thoroughbred.
