Greyhounds are some of the fastest animals on four legs. Bloodhounds have a sense of smell that's 40 times stronger than humans. And, some dogs are allergic to cats! Weird, but true! To learn more about man's best friend, Charlie and Kirby investigate how dogs evolved from one single ancestor to over 300 breeds today!

Originally released by National Geographic, 2017. Streaming video file encoded with permission for digital streaming by Infobase on January 05, 2023.