I agree, when Charly, my Great Dane, was alive nobody, not even friends who knew him, dared enter the courtyard, let alone the house if I wasn't present and tradesmen demanded he be shut indoors before entering to do work in the garden, a sensible precaution as one day a man helping me to lift a fridge to take it away for repairs found himself on the floor with his arm gripped firmly in Charlies mouth, he had suddenly leaned in to quickly and too closely to me, luckily no damage was done, no blood drawn as he was wearing something like a sturdy long sleeved boiler suit. Nothing like a Great Dane for safety but apart from being expensive they only live for 7 years, great companions and good with kids.