My keet is mostly better from his respiratory infection, but he's painfully thin and his feathers don't look healthy. Brought him to the vet yesterday, who suggested continuing the probiotic that I stopped when I stopped antibiotics, but also a vitamin supplement. I'm looking for suggestions for the supplement. I though he was getting all the vitamins he needed via his expensive food mix, but I guess he "sorts" and so is missing important nutrients. He prefers pasta and potatoes, eggs and rice to fruit and most greens. Any suggestions?