And yes, for those who have been told the natural prey animals of carnivores have vegetable protein in their stomachs, that's true. Perhaps with the increasing numbers of dogs in American homes these days, there is just not enough excess meat to divvy up to millions of dogs. The thinning-down of the meat source available to dogs, listed as the third or fourth prominent ingredient in many dog foods, just may have been necessary. Let's give the pet food industry the benefit of the doubt. One thing for sure, it was not done with the dogs' best interest in mind.
Dogs have difficulty digesting corn, which is often the number one ingredient in dog foods today.
In my travels serving meat to the dog racing industry, I noticed dog farms rearing greyhound pups on a combination of fresh meat and dry kibble. Some of the kibble used had cracked corn as an ingredient, which came out in the stool looking exactly like what went in. In The Collins Guide To Dog Nutrition , by Donald Collins, DVM, Dr. Collins explains about foods with extremely poor digestibility. The stool appears almost identical to the food as it appeared when it was fed. The most important factor in the development of all three of these is not a dog's genetic background, but its feeding program.