Regardless of what your favorite pet food manufacturer tells you, you DO need to supplement your pet's diet! Your pet is designed to digest food from "living foods" such as raw meat and vegetation. Most often the protein source in commercial pet food is inferior, and after it is cooked (heated and processed) its nutritional value is greatly diminished. Poor nutrition causes poor health. Supplementing your pet's diet with the proper supplement will help to ensure that your pet is getting the necessary nutrients lacking in commercial pet foods.