The first hairless rat terrier appeared spontaneously in a litter of normal haired rat terriers in 1972. Eventually two hairless pups, a bitch and dog, were produced from this female and they were used as the foundation stock to create the new breed of the American Hairless Terrier. As the name suggests these dogs are completely hairless except for whiskers and eyebrows. They are born with short, fuzzy, sparse hair which is quickly lost during the first 6-8 weeks, starting at the head and working backwards. Their appearance is the result of the expression of a recessive hairless gene. Once all their hair has been lost the dogs are left with soft pink skin with small spots or freckles, which enlarge with age and darken in the sun. Unlike other hairless breeds, this breed has no dental problems, breeding abnormalities or major skin problems, although sunscreen should be applied to prevent sunburn. The breed was recognized by the American Rare breeds Association and the National Rat Terrier Club in 1998. The following year the breed was recognized by the United Kennel Club (UKC) as the Rat Terrier-hairless variety. Then in 2004, the UKC deemed it to be a separate terrier breed entirely.