Dogs & cats should largely eat the foods we SHOULD eat. Lean meat, non-processed fruits and vegetables. I had a cat that loved corn on the cob, breads (no butter), and would turn down anything else for peas.
Avoid grapes, raisins, onions and garlic. Chocolate is toxic for dogs and cats. So is Xylitol, a sweeter in many candies, gums, and baked goods that is spreading to more products, including some peanut butters.