The Parson Terrier is essentially the show-dog version of the working Jack Russell. The Parson Russell is recognized by the AKC (American Kennel Club) and UKC (United Kennel Club). There's not really a huge amount of difference between the Parson Russell and the Jack Russell. A lot of the difference is actually in the politics of the different dog clubs. There is a debate over whether the Jack Russell should be recognized by all-breed dog clubs, or whether Jack Russells should stay registered under Jack Russell-specific clubs.
Although the Jack Russell and Parson Russell are officially different breeds, the same rules of training apply to both. Sign up for my free special report to find out more.
The main physical differences between the breed standards for Parsons and Jack Russells is leg length. Parson Jack Russells are required to have a longer minimum leg length to meet the breed standard. For a Jack Russell Terrier, according to the JRTCA (Jack Russell Terrier Club of America) breed standard, a Jack Russell must stand at a minimum height of 10 inches (25.4cm) at the withers (top of the shoulder blades). The maximum JRT height is 15 inches (38.1cm).
For a Parson Russell, on the other hand, the minimum is 14 inches (35.6cm) for males and 13 inches (33cm) for females. So there is no such thing as a "short Parson Terrier."
Where Does the Name Come From?
Both names come from the original breeder, John (aka Jack) Russell. Jack Russell also happened to be a parson (a clergyman), so this provided a convenient name for the other version of the breed.
Background Behind the Split
The split between the Jack Russell and the Parson Russell happened because the owners of some Jack Russells, including Jack Russell himself, didn't want the breed to become a show dog. History has shown that when working dogs get into the show ring, breeders start to focus more and more on attaining physical perfection in their dogs, often to the detriment of working qualities such as hunting instincts.
The JRTCA has actually trademarked the name "Jack Russell Terrier." The name Jack Russell is applied to dogs that are bred for their working and competitive qualities, whereas Parson Russells are recognized by major all-breed kennel clubs such as the AKC and can thus compete in the shows held by these clubs.
Is That All?
There's really not much difference between the temperaments of the two breeds. The only real difference in their character is their usefulness for hunting, as many Parson Russells have begun to lose their hunting instincts after generations of being bred for shows, although it will still be a long time before there is a big difference between the two breeds in this regard. Parsons are still hunters at heart.
Both dogs have more or less the same type of markings and both can have either a rough or smooth coat. Like the Jack Russell, Parsons are white with black and tan patches. Their care and training requirements are the same - lots of exercise and early, structured training as well as plenty of socialization.