There are alot of "Myths" about different types of dog food. I was told as a teen ager the reason KFC was so tasty was because it was fried cat. Obviously not true. It is the same with dog food.
I laughed at people who talked bad about walmart dog foods. Lower quality, not good for your pet etc. But it was IAMS and Eukanuba that had so many recalls for salmonella last year. Walmart does not make their own dog food. They get the seconds from different pet food manufacters. For example Sunshine dog food makes their current version of Old Roy regular kibble. Their high protein used to be iams but the recently changed to something else. In the older days,if the label says "meat and bone meal" it could have been the results of the dead dogs from the dog pound. They still used ground up and "rendered" dead animals for face makeup.However, that is one of the reasons to READ THE LABEL! Don't feed things like chicken by products( Feet, beaks, feathers, the dead chickens who did not make it to the kill floor, entrails etc.) as they are added to boost the CRUDE protein and are not very digestable. Some dogs have problems digesting corn which is also added to build the crude protein level. The real question is what is the digestable protein. Again, read the label, ask questions and you will have a happy healthy dog.