Overall Neapolitan Mastiff's mature and become macho, brother/father or not! So all may go well for a couple of years and then there could be a dominance battle. Certainly not always, but over two non-neutered males together is not a good idea. Now neutered is a different story. Neutered young, with no learned aggression, things will most likely work out fine.
Answered by ironnstone - 6/6/2011 3:32:04 PM