It's a complicated world
There is protein and then there's protein. You can get your protein from a vegetarian diet but then you'd be considered a nut by normal people. Don't argue. It's a fact.
I saw that CBC documentary where an old boot (a shoe, not the wife) was boiled with a bunch of motor oil (don't have exact recipe so don't ask) with some nails or something to add for essential vitamins or minerals and the dried result sent to a laboratory (stress on "or") passed on inspection as healthy dog meal. Could save a lot of money by making your own chow this way which is probably pretty close to how kibble pushers make their stuff.
If you live in a city (a big one) see if you can't find a Chinese Grocery store that sells meat they butcher on tables behind the till. I get my necks (22¢ each), legs with fingernails (24¢) bones (2$ a bag) from one and the meat looks so clean and lasts a long time (longer than from Safeways) in the fridge before I have to wash it with peroxide prior to turning into soup for the wife and kids.
The dog and I prefer the raw stuff and we both have all our teeth.
Go feed your dog kibble. To each his own. I have higher standards for my loved ones, especially me.