I have a huge, gorgeous German Shepherd.
She was a rescue with huge lack-of-socialisation issues, but when she's just at home with us, you'd never know!
So "work" is an interesting question - she is a brilliant guard dog / postman scarer / barker, and will chase a rat (or pretty much anything) given half a chance....
We sometime borrow next door's JTR for rodent murdering, if the 4 cats are out-witted