we are considering moving to a larger, more rural property and if we do, we would probably want a dog. I'd like it to be a fairly large dog, protective but not overly aggressive. We were thinking maybe German Shepard, Belgian Shepard or Lab. I know our 2 cats would not be happy about this. I'm thinking it would be best to get a puppy so they'd be the same size initially and the cats could set boundries. My kitties are approx 14 and 11 years old. We don't have complete history on either of them but we've had them both since they were a year or two old and all that time, they haven't been exposed to dogs. Any advice?