A dog can eat cereal as a treat, but cereal should not be a substitute for a regular meal. Dogs should not eat cereal that have ingredients such as chocolate or caffeine because these ingredients are harmful to dogs.
A dog should not eat an excessive amount of grains, so feeding a dog cereal on a regular basis can cause health problems. Cereals that contain a high level of sugar can cause diarrhea in dogs because dogs do not digest sugar the same way as humans do. A dog should have a steady diet that is formulated to the nutritional needs of a carnivorous animal, but an occasional treat such as cereal is not harmful.