There is a recommended daily allowance of nutrients for dogs, just as there is for humans. If these requirements are not met by a dog food, it could be considered inadequate, or "bad." Most brands strive to meet the nutritional requirements. So there are no truly bad dog food brands sold in the U.S., but varieties of food that should be avoided. One type of food from a specific brand may meet all the standards for good nutrition, while another lacks substantially. Learning to examine labels will aid in choosing a good dog food for your pet.
If the first ingredient is not meat or a meat byproduct, the dog food is generally full of filler ingredients like corn, soy or wheat. These products are less nutritious and harder for a dog to digest.
Think twice about feeding your dog a food with chemical preservatives listed on the label. Certain preservatives can cause adverse or allergic reactions in pets. Ideally, dog food should be preserved with tocopherol, which is a form of vitamin E.
AAFCO Feeding Trial Label
Foods with the AAFCO feeding trial label means that the Association of American Feed Control Officials have performed clinical trials that conclude the pet food in question meets a dog's daily needs.
Light or Diet Formulas
Foods that are labelled "light" or "diet" formulas contain less of the required nutrients needed to keep an adult dog healthy. For weight control advice, seek the help of a professional veterinarian.
Foods that claim to contain certain beneficial nutrients for preventing disease or tooth decay, or that are geared towards specific breeds of dogs do not always live up to their claims. Forgo the claims for quality ingredients.