We feed our dogs Pedigree - dry kibble, not canned. The two Shepherds also get a handful of TD every day to help clean their teeth. I don't give that to Carl though, because he never chews it, which defeats the whole purpose of it.

Once my friend left a bag of dog food in their barn and forgot about, they found it a year or so later (I don't remember exactly how long) and it was just a pile of sawdust. I don't remember what kind it was. But this tells you what kind of stuff goes into some dog foods.