Good ones will have NO gluten and NO grains (this includes rice and corn), a good protein source (meat, fish, eggs, tofu, or poultry), green leafy vegetables, sweet potato, berries and
some other fruit, fish oil (containing DHA), vitamins
, probiotics, and digestive enzymes.
The good food does not have to every single ingredient that I have listed, but will contain many of the ingredients.
Some good brands: Wellness Grain Free, Evo/Innova, Orijin canned only.