Golden Retriever Eats Purina Dog Chow

I have an older dog that is a Golden Retriever. She is about 8 years old. We feed her Purina Dog Chow and fed her Purina Puppy Chow when she was a puppy. We use Purina because it is affordable but also because Purina has a good reputation and doesn't use BHA/BHT in its ingredients. We usually buy her food at Wal-Mart or Sam's Club, but they have the best price. Now that she is older, we want to switch to something for older dogs and also a "lite" food since she is putting on weight.