How do dogs get all of their nourishment in dry food?
Many dogs don’t get all their nutrition from processed food (canned, dry, moist). That’s why they eat feces, steal from counters and raid the trash. If dry cereal had a high concentration of squared nutrition that met human requirements we could eat two bowls a day and be fine but it doesn’t. Dog food has a more rounded nutrient content which improves the higher the quality of food you buy. Cheap foods like Iams, Purina and Ol’ Roy are simply garbage in a bag/can so the dog suffers for it.