One of our dogs has an issue with wheat products. Wheat is perfectly "natural" but it gave our dog terrible skin problems which didn't go away until we removed the "natural" wheat from his diet.
"Natural" doesn't equate with "nutritious". Chlorine and cyanide are natural. That don't mean I'm going to feed them to Pugsly.
We had a miniature dachshund that was a terror. He'd get out and wouldn't come back. The only way to get him to come home was to rattle a container of "Whoppers" malted milk balls. He ate them, M&M candies, Hershey's minis and popcorn like they were going out of style. This was before we knew about chocolate being bad for dogs. He lived to be 15.