Firstly, take a look at the first five ingredients. This is not a magic number, but ingredients are listed in descending order of the “precooking” weights.
Secondly, look for a “high quality” protein to be the FIRST ingredient. (Chicken, Salmon, Trout, Lamb, Venison, etc).
When you see Chicken Meal or Lamb Meal this does not necessarily mean the food is a low quality food. This is a protein that has been dried, and clean meat//skin and sometimes bone have been used in order to create a protein. Entrails, blood, fur/feathers, hoof/feet, or horns/claws can be used when creating these.
A few dog food brands that I really like:
Earthborn
Wellness
Taste of the Wild
Canidae
Acana Regionals
Orijen
Evo Dog Food
Solid Gold
Holistic Selects
Check out these helpful links:
Dog Food Reviews and Ratings
http://www.dogfoodproject.com