Yes all dogs do. The old joke asks why a dog licks thier private part? Because they can.
Do All Dogs Lick Their Private Parts?
Some can't usually reach because of their build. Like French Bulldogs and Bulldogs. Of course it means you have to be willing to wipe your pups booty for them and do some maintenance on the females parts sometimes among other things. So the answer is no, not all dogs do.
