What breed of dog is Scooby-Doo?

I'm not walking into a supposedly haunted mansion at midnight without backup. A dog standing 30 inches tall at the shoulder would normally ease anyone's concerns, but Scooby-Doo is a dog full of contradictions. Designer Iwao Takamoto knew what a Great Dane looked like because he literally interviewed a coworker who owned one. Scooby-Doo should've been a perfect show dog with a straight back, straight legs, and a firm jaw. So why does Scooby have none of that? Why doesn't Scooby even have the right fur color? I can only assume it's because Takamoto was secretly a troll. Animation studio Hanna-Barbera was more than happy to keep defying animal genetics when it introduced Scooby's nephew, Scrappy-Doo, in 1979. Anyone who's seen a Great Dane puppy knows those things are only Scrappy-Doo size for about a week.