As a kid I distinctly remember at least one movie with an English bulldog used as a guard dog. Specifically chained up in a junkyard and running after people. As an adult I realize that am English bulldog would not be particularly suited for that role, and maybe I’m conflating things, but I still feel like this is a thing. Were there any movies with this?
IIRC, Spike in the Looney Tunes Cartoons was depicted as a guard dog. I think he was supposed to be a English bulldog, with some artistic license.
And yes, as the (former) parent of a Bulldog, I am happy to say she would have been totally useless as a Guard Dog.