breed of toy dog of ancient ancestry; it is one of the hairless breeds, its coat being confined to its head (crest), tail (plume), and lower legs (socks), although most litters also contain “powderpuff” pups with a full coat. The origin of the breed is uncertain; it may have originated in Africa, and it is thought to have been spread throughout the world by Chinese merchant ships. The gene that results in hairlessness is dominant but lethal, resulting in the death of fetal pups with two dominant genes before birth. Pups with two recessive genes for normal coats are powderpuffs.