Later Duke grew up to be large dog, as in quite large. He got along fine with our cats, but it was bad for any cat that showed the slightest sign of aggression. He would then turn from gentle into a raging fury and simply rip them to pieces.
He was always ready for a playful romp with other dogs, but woe to the one who wanted to fight.
I still miss Duke to this day, he was my best bud.