I have a 1 1/2 year old male and a 5 month old female. I am feeding them Purina Dog Chow/ Purina Puppy Chow. As this is what my dogs have always eaten. However I have noticed that their coats aren't as shiny as they could be. Could this mean a lack of nutrients. Most people on here talk about NB. Is this a good all around food for Boxers? Any help would be appreciated.