Opinions on dog food are like opinions on oil. So many choices, so many brands.
Do you go high protein, low fat, high kcal, what meat source, are potatoes or beets ok?
I did the high protein, highly recommended foods for a long time. My two dogs would have difficulty going #2, with hard dry waste, great for clean up, not so much for the hounds.
My vet walks the line between holistic and medicine, and says that unless working, the majority of dogs do not need the super high protein foods out now.
We picked a medium protein, medium fat, well balanced ingredient food, and both the Yorkie and the GoldenDoodle are really happy, going regularly and without trouble, and weights are in check.
You may want to look for a food with about 22-25% protein, about 9% fat, and something that is not sprayed with lard to make it tasty for dogs.
Purina, Gentle Giants, and Wellness have really well thought out foods.
Food reviews for what it's worth.