ジャック・ラッセル・テリア
The Jack Russell Terrier Club of America (JRTCA) was formed in 1976 by Ailsa Crawford, one of the first Jack Russell terrier breeders in the United States. Size ranges for dogs were kept broad, with the ability of working dogs awarded higher than those in conformation shows. An open registry was maintained, with restricted line breeding. Registration for the club is made at adulthood for Jack Russells, rather than at birth, to ensure the breed's qualities remain, given the open registry.