Actually, any scavenging animal (Domestic Dogs, Rats, Wolves, Hyenas, Komodo Dragons, Sharks, Crocodiles, Tigers, etc.) will feed on the bodies of humans if given the chance. Scavenging predators are often desperate for food, and they have no scruples feeding on the bodies of any species of animals. Humans are included. read more
Animals cannot be defiled, as their bodies aren't sacred in the way that human bodies are. But that doesn't satisfy the modern audience, I do not think. Hence Walking Dead's use of a pathogen detectible with medical imaging (as seen in the season one finale). read more