well I suppose that's true, they eat dogs in China, I thought that after I'd written it - but they don't eat their pets, I guess. You'd want a nice tender puppy to eat wouldn't you. Not your best mate that you took for walks, or that (in the Neolithic) helped you look after your sheep and snuffled out tasty rabbits to eat. Or something. (I don't know really. can you tell).
I would have thought generally though dogs aren't considered edible because they're carnivores / scavengers, there's a kind of taboo on them. And they probably taste a bit funny as well for that?