The Jack Russell Terrier is a small terrier that is commonly confused with the Parson Russell Terrier. The Parson Russell Terrier is shorter-bodied and longer-legged, while the Jack Russell Terrier is longer-bodied and shorter-legged. It is not yet an officially recognized breed by the AKC. The UKC recognized both the Jack and Parson under the breed Russell Terriers until 2009, and the NKC recognizes the Jack but not the Parson.
The Jack Russell dog is a small, agile, hunting terrier. Its body is slightly longer than its height. It stands at approximately 10 to 15 inches, with a compact body and short tail. The chest is the Jack Russell’s most important feature. It must be shallow and narrow, with the front legs not too far apart, giving it an athletic rather than a heavy chested look. Jack Russells were bred to hunt the red fox; accordingly, their stature had to be equipped to enter and work in the small burrows that foxes escaped into.
The Jack Russell's coat can be wiry or smooth, but is always a dense double coat. Its coloring is generally white, or white with tan, brown or black markings. Jack Russells weigh in at approximately 14 to 18 pounds. The head is broad and flat, with a powerful jaw containing a scissor bite, and straight, slightly large teeth. Jack Russells move with a jaunty, confident gait that portrays the character of the breed.
Jack Russell Terriers are characteristically high energy and very driven. Even though they are small in size, Jack Russell dogs are not recommended for apartment dwellers due to their need for exercise and stimulation. They can get restless and destructive if not given enough stimulation. Overall though, they are a merry, devoted breed.
They are also very intelligent, athletic, fearless, and vocal dogs. Obedience training is highly advised as they have a tendency to be stubborn and aggressive at times. This, combined with their loud and energetic nature, makes them great guard dogs, however.
The biggest care concern with Jack Russells is making sure they get enough exercise. Outside of that, caring for them is relatively simple. Jack Russells only need to be bathed when necessary due to their short coat. Regular combing and brushing is recommended with a firm bristle brush.
To get a Jack Russell Terrier show-worthy, its coat must be stripped rather than clipped. This creates a shorter and smoother coat that is water and bramble resistant, unlike clipped coats.
Common health issues affecting the Jack Russell breed include inherited eye diseases and deafness. Legg Perthes is a disease of the hip joints that can occur most commonly in smaller breed dogs, the Jack Rusell included. They are also prone to dislocation of the knee caps.
Jack Russells are well known for living long and healthy lives, as breeders have protected the gene pool, preventing direct in-line breeding. Given proper care, life expectancy averages about 15 years, possibly even longer. The common health issues associated with Jack Russells are generally due to recessive genes of certain lines being bred.
Reverend John Russell was a parson with a passion for fox hunting back in the 19th century. He developed a strain of fox hunting terriers from the now extinct English White Terrier, a breed that was bred to be white in color so that they could be distinguished from the quarry they were pursuing. This breed line eventually broke off into the Parson Russell Terrier and the Jack Russell Terrier.
Following World War II the need for hunting dogs began to decline drastically, and with it, the Jack Russell Terrier numbers. At that point, the breed increasingly was kept primarily as family and companion dogs.
The Jack Russell Terrier Club of America was formed in 1976 by one of the first Jack Russell Terrier breeders in the U.S., Ailsa Crawford. In the late 1990’s the AKC moved to recognize the Jack Russell as an official breed, but the Jack Russell Terrier Club of America opposed this move as they wished to keep the Jack Russell's working characteristics intact. In show, Jack Russell Terriers are not judged for their worthy physical characteristics the way non-working breeds are, but rather for the characteristics that make them excellent work companions. They lose points for exaggerations or faults that interfere with their ability to work.