I don't know much about the feeding requiremnets of Saints having never raised or owned one. As far as cow hocks, I noticed that Cody had it when we first adopted him. On his first vet's visit our vet noticed and commented on it. He wanted to do X Rays on his hips, and back legs. I waited until Cody had adjusted to us somewhat before I had it done. As it turns out Cody has displaysia in one hip. After gaining weight, which he needed to do, he is supporting most of his weight on his strong back leg and his hocks have turned a little more. I have seen Saints go through rescue here that were so bad their hocks actually hit together when they were running, to the extent that it tripped them up. Apparently, our vet guessed that he might have a problem after seeing his hocks. He explained that it is one of the signs, but certainly does not mean that all dogs with cow hocks have bad hips or knees, just that some do. If your vet didn't mention it, then it sounds like Tub just has an issue with his hocks. Hopefully that is a good thing and he has no further problems with it. Kiss Tub for me. He is such a cutie.
Kathy