Actually
I saw this and wanted to add something because I pretty avid on dog nutrition and the likes. Dogs don't need grains. It is added as a filler so the dog feels full. But as this can digest quickly it often leads the dog to eat more, which allows the dog to go through dog food more allowing you to pay more. It's a vicious cycle. But it gets the pet food industry money therefore they do it.
And wolves do not eat the stomach content of their prey unless it is small such as a rabbit. Actually most carnivores don't and if they do it is in fact very little.
This is from the site:
The Many Myths of Raw Feeding
Myth: WOLVES INGEST THE STOMACH CONTENTS OF THEIR PREY.
This claim is repeated over and over as evidence that wolves and therefore dogs are omnivores. However, this assumption is just that--an assumption. It is not supported by the evidence available to us, and is therefore false!
Wolves do NOT eat the stomach contents of their prey. Only if the prey is small enough (like the size of a rabbit) will they eat the stomach contents, which just happen to get consumed along with the entire animal. Otherwise, wolves will shake out the stomach contents of their large herbivorous prey before sometimes eating the stomach wall. The following quotations are taken from L. David Mech's 2003 book Wolves: Behavior, Ecology, and Conservation. Mech (and the others who contributed to this book) is considered the world's leading wolf biologist, and this book is a compilation of 350 collective years of research, experiments, and careful field observations. These quotes are taken from chapter 4,
The Wolf as a Carnivore.
"Wolves usually tear into the body cavity of large prey and...consume the larger internal organs, such as lungs, heart, and liver. The large rumen [, which is one of the main stomach chambers in large ruminant herbivores,]...is usually punctured during removal and its contents spilled.
The vegetation in the intestinal tract is of no interest to the wolves, but the stomach lining and intestinal wall are consumed, and their contents further strewn about the kill site." (pg.123, emphasis added)
"To grow and maintain their own bodies, wolves need to ingest all the major parts of their herbivorous prey,
except the plants in the digestive system." (pg.124, emphasis added).