If your dog is doing well on a food that contains grains, there is no reason to change it. You should never make drastic changes to your dog foods unless you have to.
There is some evidence that a grain-free diet can cause harm to the wellness complete health of some canines. They may gain weight because of the alternative carbohydrates in the recipe. Diets that lack grains can also affect the blood levels of taurine and that can cause serious problems for the heart including cardiomyopathy.