I hope it doesn't come to needing the taser but you have to do what you have to do. Just out of curiosity, how much does the owner weigh?
J/K but he sounds like a real prince. I wonder how he is going to feel when his "real" dog really hurts someone.
Hopefully, you'll be able to get out of your lease if that's what you want. Seems like the best solution for you and Bruce if nothing else can be done.