Bullmastiff-~the has a mind of his own — and considering that he weighs in at pounds, he can easily overwhelm an owner who isn’t ready to stand up to him. He needs good, consistent, positive training and firm boundaries from a young age.
Bullmastiff's are intensely loyal to their family and doesn't like being left outside. If they don't get enough companionship or personal attention, they may walk through fences just to be with people. Xena might need another large friend :) someday!