This article also relates to: Parson Russell Terrier
Perhaps one of the most well-known breeds, the Jack Russell Terrier takes its name from the Reverend John Russell who began its development in the early 19th century. Primarily bred for the purpose of hunting small game and digging out den quarry, the Jack Russell Terrier established a concrete reputation for itself as an independent and able-bodied working dog. Despite enjoying wide popularity throughout its early existence, following WWII the demand for hunting dogs declined, subsequently along with Jack Russell Terriers. Increasingly the breed was observed in the domestic setting, both as a companion pet and show dog. The American Kennel Club recognised the breed in 1997 although the name was changed to the Parson Russell Terrier due to trade marking.
In order to keep up with the hounds when hunting badger and fox, the Jack Russell Terrier had to have relatively long legs. This trait was selectively bred into the Russell Terrier, along with its compact, athletic build that made it capable of maneuvering into tight spaces to delve out den quarry. Further characterising the breed is its tenacious disposition, pronounced muzzle, narrow chest, triangular 'drop' ears and dark eyes. The coat is typically short, smooth and close-fitting, often observed in colours of white with tan or black markings. The dense, double coat serves to insulate the dog whilst acting as protection against bracken and rough underground earth. The modern Jack Russell Terrier is seen in hunting, tracking, agility and performing tricks.
Highly energetic and intelligent, the breed requires both physical and mental stimulation in order to discourage destructive behaviours around the home. The Jack Russell Terrier is characteristically loud, making for a great watch dog. It is not uncommon for a Russell Terrier to display signs of stubbornness or aggression so early socialisation and firm leadership is important. Otherwise, a Jack Russell Terrier is typically cool, calm and collected, making a great addition to active family life. A healthy Jack Russell Terrier will weigh 6.5-8 kg, with a life expectancy of 12-14 years when shown the appropriate love and care.
Eye disorders are particularly prevalent in the breed, ranging from cataracts and entropion, to glaucoma and anterior luxation. Other conditions include congenital deafness, orthopedic complaints and arthritis, and von Willebrand's Disease, a rare bleeding disorder.