My pup started on EVO at about 5 months old. The package says that it is for all life stages, including puppy - you just have to feed a puppy a bit more than an adult because they're so active and have so much growing to do. Before EVO he was on Chicken Soup for the Puppy Lover, and had never had a decently well-formed stool. He also gained weight very slowly, constantly looked really skinny and hunched over a lot, never ate the recommended amount, and we almost always had to hand-feed him.
As soon as we started gradually switching over to EVO, his stools started to become more normal, and now almost all of his poops are nice and firm (yay!!). He will also actually eat out of his bowl fairly often, and on days when he gets a good amount of exercise, he eats the whole amount that's recommended for his age and size. He's also filled out a little bit, and we can only feel his ribs - not feel AND see. We're only a couple weeks into feeding 100% EVO, but he's also already scratching himself less too, so I suppose he was probably allergic to one of the grains in his old kibble.
Anyways, we're really happy we made the switch when we did. He seems so much happier and healthier now, in so many ways. We'll know more though I'm sure in a couple weeks - he'll be getting all his bloodwork done for his neuter. I hope he's actually as healthy as he acts.
Lauren & Nikko
PS: I asked my vet about EVO too... she said she'd never heard of it, and that we certainly should be feeding something she knows more about, like science diet, and she tossed me a bag from her shelf that she assumed I would then buy. I just smiled, said thank you, and put it back on her shelf. LOL... for the most part, I do still like my vet.