This is anecdotal, but my mother’s old dog didn’t like the kibble she was feeding it. Instead of shopping around for something the dog DID like, or just letting her get hungry enough to eat the kibble, she started buying big bags of cat kibble. (She’s noticed that the dog would eat the cats’ food, given the chance.)
She thought she’d done something clever, since her dog finished the food and licked up every crumb. But after awhile, the dog started getting sick. The vet told her she was dangerously close to ruining the dog’s kidneys, and not to feed cat food any more.
I did find an article to back this up: http://www.vetstreet.com/our-pet-experts/why-does-my-dog-make-a-beeline-for-cat-food
“…long term it is not good for a dog to eat primarily cat food, Dr. Crowell-Davis says. It’s not properly balanced for them in terms of the fiber and protein and certain nutrients. Plus, it can be hard on their liver and their kidneys to have so much protein.”
It really sounds like cat food is formulated with too much protein for dogs, since cats are obligate carnivores, not omnivores. I would think that finding a quality cat food with the correct amount of protein for dogs would be difficult, if not impossible.
I suppose you could feed a percentage of cat food along with some rice or something of that nature, but if you’re doing all that, why not just feed raw?
