My one year old Bernese Mountain Dog will not leave my cat alone. Whenever the cat is around, Henrik (my Berner) will nudge at the cat, put his paws on him, mount him, and play bite him. Nothing I do, short of separating them, will stop him. Thankfully the cat doesn't mind all that much (he's usually very calm), but I can tell that sometimes it stresses him out. And it certainly annoys the hell out of me too. It used to be cute when he was a puppy but now I just feel bad for my cat. Right at this very moment I can hear Henrik panting and stomping around while he chases him up the stairs.
What can I do to make Henrik treat the cat with more respect? How do I show him that the cat is not a toy?