Raw meat. Unlike us, they can manufacture all the other vitamins they need.
Even consuming meat from a variety of different species, and regularly eating organ meat, off the top of my head you would still definitely be deficient in vitamin c and vitamin k.
Edit (I was curious about the eskimo paradox): It turns out that whale skin is a fairly good source of vitamin C, and the process of fermenting meat causes it to become rich in vitamin K. So if you are willing to consume whale skin, liver and fermented meat regularly, you too can survive on a diet comprised entirely of animal products! I'm still sure the eskimo diet is far from optimal in terms of health and fitness.
Dogs don't need vitamin C. They manufacture their own. Don't know the specifics of K off the top of my head, but dogs are not humans. They may be mammals but they do not have our biology.
My dogs eat mostly chicken leg quarters and pork neck and they're thriving. I'm saving incredible amounts of money on food and vet bills.
If you want more info look up the research of Dr Tom Lonsdale that has been suppressed by dog food companies for years. His book Raw Meaty Bones has everything you need to know.
Did you ever consider how our dogs were fed before kibble existed? Or why we don't feed pet snakes and lizards some meal replacement?
Meat. Bone. Very little fat. No organs.
We couldn't handle that. Dogs can.