First, look at the ingredients.
Many dog food companies make crap; I've read that years ago, they discovered this market as a profitable answer to get rid of some of their junk.
Regarding canned, keep in mind the three-D's; i may be that the animal was either dead, diseased, or dying and therefore found to be unfit for human consumption.
Many of the dry foods are filled with filler (junk) that your dog doesn't need. Look at the ingredients, what's listed? Things like "by-products," or grain or "brewers ..." are the cheapest and most likely to be unfit for human food / leftovers / garbage. Do a little research.
Example: For dry, I use Innova large breed puppy food, or Blue Buffalo large breed puppy food.
*** Note that the previous two puppy food examples are specially formulated for large breeds - this is important, as too much protein in their diets at this stage can lead to problems.
My pup gets mostly dry, but in addition she gets occasional vegetables (like frozen carrots) fruit and maybe occasional egg, yogurt or even an occasional piece of raw beef (like a rib or a low-cost steak that's not very thick and lots of bone). Try to limit the protein as mentioned earlier.
And lots of mental and physical exercise.