Which breed holds records for incredible speed and is considered the fastest dog?

The story behind the answer

Greyhounds are the fastest dog breed, clocking around 45 mph (72 km/h). Their speed comes from a race-bred design: long, aerodynamic bodies; a deep chest with a large heart and lungs; a highly flexible spine; and powerful hindquarters enabling a double-suspension gallop (all four feet off the ground twice per stride). These features give them explosive acceleration and top-end speed that outpace other sighthounds.

Context helps: Whippets are “mini sprinters” (~35 mph), Salukis excel at endurance and desert coursing (~42 mph), and Borzois are swift but not record-holders. Memory tip: Greyhound = the “track star”—think racing dogs chasing the lure.