A Greyhound named Star Title set the world record for the fastest dog by running 41.83 mph (67.32 km/h).

On March 5, 1994, a Greyhound named Star Title was timed at 41.83 mph at a track in Australia. Most pet dogs only run between 15 and 20 mph. Greyhounds can reach these high speeds because their bodies are built differently than other breeds.A Greyhound heart is much larger than the heart of a normal dog. It makes up about 1.18% to 1.73% of their total body weight. This large heart pumps a lot of blood with every beat. Their blood also has more red cells to carry oxygen to their muscles quickly.These dogs use a movement called a double-suspension gallop. During a sprint, the dog is completely in the air two times during each stride. One jump happens when their body is stretched out. The second jump happens when their legs are tucked under their chest.Their long spine is very flexible and acts like a spring. This allows their back legs to reach far forward for a stride length of 15 feet. Their muscles are mostly fast-twitch fibers which create a lot of power very fast. Their deep chests also give their lungs plenty of room to breathe during a race.