The Chinese crested dog is devoid of hair except for the crown of the head, lower part of the limbs and tail. The breed is produced by a dominant gene for hypotrichosis (Hr) in combination with the gene for long hair (l). The homozygote HrHr is a prenatal lethal, hence the Chinese crested dog is an obligate heterozygote. The long haired segregants, ++ ll, are known as powderpuffs.