Basenjis, the only barkless dog, can be traced back to Egyptian times.
Basenjis are hounds with a wrinkled forehead, a curled tail and almond-shaped eyes that convey a variety of humanlike emotions. They do not bark, but they do communicate with an odd sound described as a yodel.
According to paleontologists, Basenjis look a lot like the first domesticated dogs. Before becoming a favorite breed with the Egyptians, they accompanied African tribesmen in hunts, and were known expert vertical leapers to scout prey in the grasslands. The dog was introduced to England in the late 1800s, and was favored for its speed and bravery. It later came to the US, and was recognized by the American Kennel Club in 1943.
Not only are Basenjis unique for not barking, they also lack doggy odor, clean themselves all over just like a cat would, and females only come into heat once a year (instead of twice like most dogs).