Originally Posted by Lace

As Steve said, the Mastiff may be a bit intimidating for models or kids. Depending on the breed of Mastiff, they can be very large. I've had people scared of my 70lb Husky + Akita mix so I couldn't imagine a 140lb dog. Just do your research on the breed you're looking at and if you can, spend some time with the dog you're looking at and make sure you two get along.