The Jack Russell Terrier, also sometimes called the Working Russell Terrier, the Working Jack Russell Terrier, the Jack and the JRT, is a lively little dog named after its originator, the Reverend John (Jack) Russell, who was an English parson in the 19th century. Jack Russell Terriers were bred to accompany the hunt and go to ground to bolt fox. Ultimately, they were bred for temperament and ability rather than consistency in type. An interesting fact about this breed is that a Jack Russell Terrier is the only dog ever to have set paws on both the North and the South Poles. Explorers Sir Ranulph Fiennes and his wife, Ginnie, apparently took their JRT, Bothie, on both of their transglobal expeditions from 1979 to 1982. Jack Russell Terriers are best known for their intense curiosity, extreme intelligence and endlessly entertaining personality. The Jack Russell Terrier is not recognized by or eligible for registration with the English or American Kennel Clubs.
The adult Jack Russell Terrier typically stands 10 to 15 inches at the withers and weighs between 11 and 13 pounds, although there is great variability in the size and appearance of this breed. The JRT comes in three coat types, all of which are virtually weatherproof: smooth, rough and broken. Their coat requires minimal care.