From fluffy floofs to lean mean zooming machines, this quiz covers 40 dog breeds ranging from everyday puppers to rare canine royalty. Think you can tell a Samoyed from a Spitz? A Ridgeback from a Rottweiler? It's time to put your bark-knowledge to the test. Warning: some questions may cause extreme tail-wagging excitement or unexpected whimpering. Score well, and we might just throw you a treat (or at least a virtual belly rub). Let's see who's a good quiz-taker—yes you are!