There is no way anyone would even get on the property if Shadow were outside. Without any training at all, he does a perfect "bark and hold"... And if anyone comes to our front door, he is up and facing out the glass at them, barking his head off, showing every single one of his very pearly white teeth.
These dogs even think it is their responsibility to chase off the crows, hawks, and other large birds that dare fly over the yard... I have no worries about varmints in my veggie garden, or deer munching on my landscaping, thanks to the two of them...
Folks, don't rush out and get one, though. They need a job to do, daily exercise, and can't be just tied out in the yard. Obedience training of some kind is a must, and they are not at all like labs... while they are very faithful and loyal to family and close friends, they are aloof with strangers and other dogs, and can appear hostile to these...
Stay Safe !!