[quote=4iso] They are not stuburn they are THINKNING that is why they are different from the others.[/quote] :lol: Yep! I'll chime in and say that even if your dog isn't a roamer, as mentioned before, because of the size and intensity of these dogs when they go into protection mode trying to rely on an electric collar to stop them is just asking for problems. With some of them even having a physical barrier there isn't always enough. There's also problems with rodents chewing through the wires and the system shorting out. It could be down and you wouldn't ever know it until the dog was already gone and/or you checked the control box. Many dogs like this are smart enough to know and respect the invisible fence... however they will still test it constantly just to see if it is still working. Even if you could assume that your dog respects the invisible fence and doesn't go outside of the area, what will happen when there's another dog that wanders into the yard? I think the best bet is just a phyical barrier plain and simple.