I feed my adult chi Tango, Innova Evo, the Red Meat Small Bites. He's 3.9 lbs. He's done extremely well on it, it cleared up a variety of issues he had when I rescued him at 7 months. I temporarily added in some Merrick Turducken, but he began gaining weight so I stopped.
I also have a 5 month old puppy, Jazz, that I rescued at 11 weeks. She's on the Merrick Puppy plate till she gets a bit older, when I'll switch her to Evo too. I prefer grain free, but the Evo's not for puppies which I why I chose the Merrick brand for her till I can make the switch. She also had medical problems when she was rescued, and the Merrick has done a good job of making her strong.
They (Merrick) also make a canned food that both dogs absolutely LOVE, and I give it very occasionally as a special treat. It's called Puppy Plate, and while it's for puppies it's nutritionally sound, so Tango gets it every now and again (like maybe once a month.) It's human grade, no additives, smells yummy, and neither dog has had any digestive problems with it, no soft poops, no issues at all.
You might want to give that a try.