Okay, so this isn't any time soon, because my youngest puppy still isn't even full grown just yet. But I work evenings and my wife and daughter are home alone at the house from 6pm-3am and i'd like to have a good family dog that would actually be good as a guard dog too, in case anyone broke into my house and attacked my family. I was thinking a Collie because they're big enough to defend and they're excellent family dogs. But honestly, how would they fair as a guard dog if my family was in danger against an intruder? I mean, my current dogs (Shelties) would be of no use to them, they're great watchdogs with a very loud mouth, but they'd never attack, and even if they did, they're so tiny it would just be a small kick to beat them. I don't want a mean or aggressive dog at all, it will be totally indoors with my family (my daughter is 5) so it needs to be gentle, but brave and an excellent defender if necessary. Any ideas?