needless to say he soon found himself living in the back yard 
that's sad for nitro!
Big dogs are nice but a pain to wheel with most of the time.
I would have to say probably the best size dog to have as an all around protective but great to wheel with dog is one of those midsize breeds (or better yet, mutts). They are big enough to be threatening but yet basically portable at 20-40 lbs or so. If you are going to have a large dog it has to be trained to a tee, not just sort of trained.
Not that it isn't great if they are all trained to a tee but it's a lot harder to deal with a not so well trained big dog.
