Originating in the early 19th century from dogs bred and used by Reverend John Russell, the Jack Russel Terrier has similar origins to the modern Fox terrier and is commonly confused with the Parson Russell Terrier the American Kennel Club (AKC) and affiliate variant) and the Russell Terrier. Although considered by many to be one in the same as or a different variety of the Parson Russell Terrier, fanciers of the Jack Russell consider it to be a unique working terrier breed, whereas the Parson Russell is a conformation breed. The Jack Russell is a broad type and the name is often misapplied to any small white short haired terrier breed. The typical "Jack Russell Terrier" should be within a size range of 10–15 inches, the Parson Russell is typically the next size down with a standard size of 12–14 inches, while the Russell Terrier is the smallest of the trio at 8–12 inches. Each breed, however, has different physical proportions according to the standards of their breed clubs.
For detailed information regarding the ancient history and origin of the Jack Russell Terrier please see the History section of the Parson Russell Terrier for more information.
The Jack Russell Terrier and Parson Russell Terrier are considered by many to be one in the same breed, save different breed standards. From 1997-2003, those members of the breed between 13-14 inches were recognized by the American Kennel Club (AKC) as Jack Russell Terriers. The 14 inch standard used by the AKC was favored by the Jack Russell Terrier Association of America (JRTAA). Founded in 1985, the JRTAA was also the official breed parent club for within the AKC at the time. However the Jack Russell Terrier Club of America (JRTCA), founded in 1976 felt the standards were two restrictive and favored a height requirement of 10-15 inches instead. By 2003, in-fighting and bickering amongst fanciers on both sides led the AKC to change the name to Parson Russell Terrier. Dogs that were previously registered as Jack Russell Terriers thereafter became known as Parson Russell Terriers. The JRTAA also changed its name to the Parson Russell Terrier Association of America (PRTAA) and remained the official breed parent club.
This left the name ‘Jack Russell Terrier’ unrecognized within the AKC but far from gone. The JRTCA remained active and held firm to its opinion that the “Real Jack Russell Terrier” may be any height between 10” and 15” and that there is no “ideal” size; as ideal is the perfect size to perform the job the owner requires. Today the JRTCA touts itself as “the National Breed Club and Registry for the Jack Russell Terrier in the United States and the largest Jack Russell Terrier club and registry in the world.”
There remains substantial disagreement among breeders, fanciers, kennel clubs, and experts as to how to treat the difference between the Jack Russell Terrier and the Parson Russell Terrier. The most common treatment is to consider the Parson Russell Terrier as the conformation show variety of the Jack Russell Terrier breed. This is the treatment shared by virtually every major national and international kennel club, including the AKC. The UKC further confuses the issue by calling their dogs the Parson Russell Terrier, but use the broader Jack Russell Terrier standard. In essence, the UKC is saying that the two breeds are the same, and the official breed name is the Parson Russell Terrier.
However, many organizations take different stances. Many members of the PRTAA believe that the Jack Russell Terrier is not a breed at all, but rather a generic type of dog similar to a retriever or spaniel. Similarly, while most JRTCA members consider the Parson Russell Terrier to be a variety of Jack Russell Terrier, others argue that since the breed does not have the working ability requirements for registration that these dogs are not Jack Russell Terriers at all. The Australian National Kennel Council (ANKC) and the New Zealand Kennel Club (NZK) are the only two major canine bodies that treat the Jack Russell Terrier and the Parson Russell Terrier as two unique breeds and register them as such.
Thanks to the breeds many appearances on film and television, the Jack Russell Terrier is among the most recognizable dog breeds in the world. The Jack Russell Terrier closely resembles the original working style of the Fox Terrier, which is in fact just what the Jack Russell Terrier is. The JRTCA wants as much genetic diversity in their Jack Russell Terriers as possible, and as a result the breed is considerably more variable in appearance than most purebred dog breeds. This is a small terrier breed, and breed members should be between 10 and 15 inches tall at the shoulder.
The typical weight range for the Jack Russell Terrier is 14 to 18 pounds, although working dogs may weight slightly less. As is the case with all dog breeds, male Jack Russell Terriers tend to be slightly larger than females although this breed exhibits less sexual dimorphism than most. The Jack Russell Terrier exhibits a greater range of body and leg types than most breeds. While many Jack Russell Terriers are long-legged, with the balanced body proportions of a Foxhound, others are short-legged and long-bodied like a Corgi, although not to those breeds’ extremes. Breeders strongly desire for this breed to maintain its working instincts and as a result this breed is extraordinarily muscular for its size. The Jack Russell Terrier’s tail is roughly four inches long, and sturdy enough to firmly grasp. This tail is typically carried upright.
The Jack Russell has a head and muzzle that are well-proportioned to the size of the dog’s body. The muzzle should be slightly shorter than the length of the head. The breed’s muzzle is not overly wide, and tapers slightly towards the end. At the end of the muzzle is a typically black nose. The eyes of a Jack Russell Terrier should be almond shaped and dark in color. The overall expression of the Jack Russell Terrier is one of energy and determination. Jack Russell Terriers are known for their distinctive ears. These ears are held partially upright, but with the front folded down. The ears face forward and are typically held high on the head.
The coat of the Jack Russell Terrier comes in three varieties, smooth, rough, and broken. All three of these varieties are comprised of short to medium length fur. Additionally, all three varieties have a double-coat, with an undercoat of softer fur. The smooth coated dogs have smooth fur, which must be dense enough to provide some protection from the elements and cuts and must never be silky. Wishbone and Jim Carey’s dog in The Mask were both played by smooth-coated Jack Russell Terriers. The rough-coated Jack Russell Terrier has the traditional wiry-terrier coat found on such breeds as the Cairn Terrier or the Wire Fox Terrier. Eddie from Frasier was played by a rough-coated Jack Russell Terrier. The broken-coated Jack Russell Terriers have a coat which is intermediate between the smooth and the rough. These dogs often have longer hair on their faces, giving them the appearance of having a beard or goatee. Neither the rough nor the broken coated Jack Russell Terriers should have a wooly coat.
Jack Russell Terriers should be primarily white in coloration, and their coats must be at least 51% white. Most Jack Russell Terriers are probably closer to 80% to 90% white. These dogs typically have the most white on their stomachs, legs, sides, and tails. This breed typically has brown, tan, or black markings. Most dogs have only one color marking, although some may be tri-color dogs. Brindle markings are unacceptable in the Jack Russell Terrier. The most common places for markings to be are on the ears, over the eyes, and on the sides.