Pet dogs in Bronze Age given vegetarian diets! Do not ever try this at home, but it looks like Bronze Age dogs were vegetarians! According to a study of protein in 3,000-year-old canine bones that is. A new study published in the Journal of World Prehistory shows that in the diet of 36 dogs, 10 of the dogs whose remains were tested were omnivores, primarily fed cereal grains like millet. On the other hand 17 of the dogs showed signs of eating almost no animal flesh, which was hard to determine if this was just showing the cattle they guarded, or their diet. With no need to tear meat, Neolithic dogs evolved to have weaker jaws than their wolf ancestors, making their jaws better suited to crushing grains.