Answer:
By wild dogs, you mean wolves: the natural diet of wolves is anything. Although they are primarily carnivores (meat-eating) and eat anything from mice and rats to caribou or bison, or even carrion, they do also eat grass, berries, and other edible things they find in nature.
If by wild dogs you mean feral domesticated dogs: these are scavengers primarily and subsist on anything edible. They often live on the periphery of or within human settlements and eat any form of garbage/waste food.