GM

Grains are optional in a dogs diet and should not be fed too much. They are not build to digest raw grains. In the wild they would eat predigested / fermented grains from the stomach of their prey.

IMO a good diet has 70% meat and 30% veggies and and fruits. The ratio of meat can be even higher but always have a look that the dog should have vitamins like D3 and minerals. Good ready-to-eat dogfood will be have them added.