How do you decide what animals are morally okay to kill for food? Chicken? Snake? Dog?

I do have to agree with Andrea. Having grown up on a farm (sort of) we often ate our pets. It has been a long time since those days. I will tell you this though, you mention food (for lack of a better word) from McDonald's and possibly Domino's, this is not food. It is dead food and it is killing. I would rather eat my dog before I ate the crap they serve in fast food (again, for lack of a better word) restaurants. So, the line is to be drawn at real food and dead food. Not if it is a dog or a fish or a parrot or a pig or a cow or a horse etc. etc. etc.