Raw food diets might be the oldest form of pet food; after all, they are very close to what ancient dogs used to eat.

A raw dog food diet typically consists of:

Muscle meat, often still on the bone.
Bones, either whole or ground.
Organ meats such as livers and kidneys.
Raw eggs.
Vegetables like broccoli, spinach, and celery.
Apples or other fruit.
Some dairy, such as yogurt.