Whenever bullmastiffs are mentioned they cop a lot of crap, and I'm sre there's truth to it, I understand the watering down of show breeds and etc, but then I also have real life experience with bullmastiffs and the ones I came across were anything but watered down. If they had a "weakness" from my perspective it would be that they seemed too intense. Relatives of mine have had them and they seem to be the kind of dog that's always trying to climb fences to kill cats and the males are really macho trying to fight other dogs all the time. And these are real negative attributes from my perspective, not what I want in a dog, but it's just that it's the complete opposite of the "watered down" image they are always portrayed as. They're supposedly lazy with depleted drives and unfit, the ones I've known were too energetic, with drives that were too intense for the people who owned them, and they were also in really great shape and quite physically capable, able to run very fast and jump fences they weren't supposed to. I know more bullmastiffs that were given away and even put to sleep for being too much dog than any other breed. For doing things like climbing next door and killing the neighbours cat under their house, breaking through the fence and chasing the mail man, injuring other people's dogs etc, real problematic behaviour and I'm not saying it's good, all I'm saying is it doesn't fit the description of the watered down lazy lump of a soft dog bullmastiffs are supposed to be.