Well, let's see... from a survival standpoint, I'd be stupid to eat Dakota. He is a good hunter and would protect me if necessary. I'm sure that with a little demonstration, I could teach him to catch fish, too.
Ripley.. what would be the use in eating him anyway? There's practically nothing on him. He's just skin, bones and organs.
Seriously though, if I had no other choice but to eat one of my dogs or starve, I think I'd starve. I would do a lot to survive, but if it came down to killing and eating my devoted partners, I don't think I could do it.