Dry, canned or raw? All are fine choices, but each has its pros and cons. Dry dog food is the least expensive to buy among foods of equal quality, and more convenient to store, but you should at least supplement with canned, raw or homemade food, according to experts such as DogFoodAdvisor.com's Mike Sagman and DogAware.com's Mary Straus.
Canned food tends to be higher-meat, lower-carb and contains fewer preservatives than dry (because the canning process itself acts as a preservative). Canned dog food also lets dogs get more moisture from their food, which helps them stay properly hydrated and benefits the urinary tract.
Raw food gets closest to dogs' wild diet. You can make it yourself, or buy it in frozen or dehydrated form.
Which life stage? Only two life-stage designations have any real meaning: puppy and adult dog. Those are the only two regulated by AAFCO. Puppy formulas generally have more calories and protein. Products labeled "senior" or "large breed" simply meet requirements for regular adult food. There's nothing regulating those additional terms when they're used on dog food packaging.
Observe your dog carefully when trying a new food. Some dogs need more protein and some need less, just as some dogs need to eat more than others, depending on activity level. Look for changes in coat and skin, along with stool consistency.
Pet-food safety is a concern. Past and recent recalls of dog foods have spotlighted some major issues regarding pet foods and their ingredients. Although pet owners need to be vigilant, also be careful to not be swept up by unsubstantiated rumors. Check the FDA website regarding recalls, and buy the best quality dog food that your budget will allow.
Should you cook for your canines? If you have the time and inclination, you can make your own homemade dog food. On the plus side, it's one way to ensure your dog is getting the best quality ingredients -- and at a cost that's will typically be lower than buying a commercial, quality dog food. A typical homemade raw-food meal might include chicken backs, necks or wings, a couple of beef ribs and an egg. Fish is also highly recommended; an entire raw fish is considered a real treat.
The downside is the time making your own dog food would consume. You also need to be careful that your home-made meals are balanced and provide the complete nutrition that your dog needs. That can be done by feeding a varied diet with the proper foods in the right proportions, with a little help where needed via vitamin and mineral supplements
There are lots of good resources on the Internet where you can learn more about homemade dog diets, but a good starting point is the Homemade Diets for Dogs section at DogAware.com. There Mary Straus lists a ton of helpful information and guidelines, sample diets, supplements and more, including some useful links to other homemade dog diet resources.