It depends on the breed of dog. Cats can reach a speed of 30 miles per hour. Greyhounds can run 43 miles per hour. Some other breeds that can run at a minimum of 30 miles per hour or more are Salukies, Whippets, Border Collies, Vizslas, Alaskan Huskies, Jack Russell Terriers and Doberman Pinschers. So if a cat raced against a Greyhound or Doberman, it would be the loser.