Jack Russell Terrier

The Jack Russell Terrier is a working terrier breed created in England during the nineteenth century to hunt foxes underground.

Reverend John Russell established the foundation stock in Devon during the early 1800s, selecting white-bodied terriers that could pursue quarry into subterranean dens without mauling the animal. Australian breeders later refined the low-set working strain and drafted the first formal standard in 1972, establishing the Jack Russell Terrier Club of Australia. The Fédération Cynologique Internationale accepted the breed under Group 3 for Terriers, designating England as the country of origin and Australia as the country of development.

The ideal height at the withers ranges from 25 to 30 cm (10-12 in), with an optimal body weight calculated at approximately 1 kg per 5 cm of height, translating to 5-6 kg (11-13 lb). The body is rectangular with a flexible, compressible ribcage spanning 40-43 cm (16-17 in) behind the elbows to allow easy underground maneuverability. The weather-resistant coat comes in smooth, broken, or rough textures. White hair must dominate the body, accompanied by black markings, tan patches ranging from light shades to chestnut, or tri-color combinations.

The breed standard defines the dog as bold, fearless, friendly, and quietly confident. Due to an intense hunting drive, daily exercise through vigorous walks and structured games is essential to avoid boredom. Grooming involves weekly brushing for smooth coats and occasional hand-stripping for rough or broken coats to remove dead hair. Documented inherited health concerns include patellar luxation, primary lens luxation, hereditary cataracts, deafness, and spinocerebellar ataxia.