Hey Bob,
Feed your dog a good whole foods diet.
There are a few food toxicities in the literature such as chocolate (in a people world where it is considered food), plus disasters with onions, macadamias, grapes and avocadoes (dose dependent poisonings - more likely in an under nourished, unsated dog). Well meaning people will focus on those when feeding fear.
Domestic dogs are adapted to living with humans. As a puppy, when vets fear monger about growth and skeletal development, feed some breed appropriate (sized) raw 
beef or sheep bones to provide the minerals. Always stay with a puppy while it chews the bone. Chewing is important for a dog’s mental health.
Look for flat trabecular bones like sheep sternum (brisket) rather than sharp pointy bones like back bones and chop bones. Think carefully before feeding cylindrical leg bones, cortical bones can damage dogs’ teeth. But a split beef marrow bone can be a meal for a day. Small breed pups and cats can chew on chicken wing tips quite safely. Keep the beef and chicken bones in the freezer, if you stock up.
Billie (Lab pictured above) has never seen a processed dog “food” from weaning. She is not ‘greedy’ for food, even though the breed has a ‘greedy gene’, and the norm at the dog park is to lament a Labrador’s food drive (I, like you, suspect they are under nourished). So, she doesn’t fuss over food, or tip over rubbish bins like other Labs do.
The pet food companies are owned by the large food companies, mainly. Grains are a cheap substrate on which to pile profit.
Billie is OMAD on fatty beef, egg, sardines, full-cream yoghurt. Now she is adult she gets to eat a raw, frozen chicken frame every second day. She gets raw frozen chicken necks for positive training (or so she doesn’t dawdle following her nose when we have to be somewhere). She gets beef bones from the freezer when left at home, and bone broth, when I share. She probably eats better than I do.
The only side-effects to note are that she is bigger, stronger, brighter, shinier, more active and better looking than any other Labrador that we meet.
I wrote too much in the wrong thread. My apologies. Probably better in one of these threads: https://www.ketogenicforums.com/search?q=pet%20food
(I’ve got a veterinary degree, 30+ years of clinical experience, and we did do Nutrition training for 6 months of a 5 year degree - back in the 1980s.)
!
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