Question: is cooked onion bad for dogs?
Answer: All parts of the onion plant are toxic to dogs, including the flesh, leaves, juice, and processed powders. Raw or cooked, fried or powdered, onions and the rest of the allium family (garlic, shallots, leeks, and chives) are harmful to dogs. Onion powder is in a surprisingly wide range of foods, from soups to baby food.