Years ago; probably close to 20 I asked my vet at the time if it mattered if I bought generic food or the more expensive brands. He said "there is no difference in dog food; why spend more?" As I said that was a very longtime ago and I have come a long way since. I no longer feed dog food preferring to offer my dogs "real food." I do not call it "people food," to me people food is pizza, pancakes and bacon, tacos you know the stuff we humans love to eat but know that we shouldn't.
Real food is just that, good natural food like meat, veggies, fruit and grains. I do keep a very high quality dog food on hand and feed it occasionally just incase there is a time when I need to go away in a hurry. This ensures that my dogs are use to the food and whoever is here with them can feed them this in my absense. The brand I choose is Orijen
Feeding your dog a real food diet is not difficult; yes it is time consuming but it is well worth the effort. Many people don't prepare their own meals and are not likely to spend the time making food for their dog. For those who have no interest in real food for the dogs; do your research and purchase the best, high quality dog food that you can. And I can guarantee you that you cannot buy good dog food at Walmart or the grocery store so if that is where you are buying your food, change.
The best place to buy good, high quality dog food are some of the smaller privately owned pet stores like Pet supply warehouse or Wild's Pet Food in MV, for those of you in my area. Anyone not in my area; there are good pet food stores everywhere, you just have to look around. Do your research about food and select the best you can find. Here is a great link to check out foods.
Now, if you are interested in cooking for your dog or feeding raw there are also a ton of sites with loads on info about it as well. Even if you aren't interested in preparing your dogs food from scratch, adding some extra meat, veggies and fruit every so often can be very nutrious. And one of the most important things that is against what most people have been told, switch it up. Do not feed the same thing all the time. A variety of foods is the best way to make sure your dog is eating a well balanced and rounded meal. As well, if they are accustom to eating different things all the time they won't have diarrhea if they have something different.