Just look at the ingredients, and read up on what nutrition "by-products", "corn", and "grain" will provide your dog. Not much, at all. IMO, feeding dog food full of junk that dogs cannot digest (hence Karen's comment about poops, the waste that they produce is a result of all of the grain/corn/sorghum that they cannot digest, and therefor is useless to their body) is equal to people eating chips & sugary cereals as a basis of their diet. Look for a kibble with absolutely NO corn, NO soy, NO wheat/grain, NO by-products, and with at least 2 of the top 3 ingredients being a specific meat (preferably Chicken meal, Lamb meal, or Turkey meal). The more meat protein in the kibble, the less waste your dog will produce and the less stress it will put on the disgestive tract. You will also see improvements in coat, skin, eyes, ears, energy, etc, if you feed a more species appropriate diet (which means more meat).