Do you have an older dog? Dog care at this age is vitally important to their daily lifestyle. Dogs that have pain in their joints need help getting up onto beds and couches. Create a step system for him to do this. Also, if you have steps leading out of your home, try to find a way to minimize how steep they are as this is painful for many older pets.
To help to improve your dog's diet, switch your dog's food slowly. Incorporate his new food into his old food for a couple of days. Gradually get him off the old stuff and onto the new. This is helpful when it comes to moving from poor quality food to healthy foods without rejection.