Russell Terriers were originally bred by Reverend Mr. John Russell, who was a parson and loved to hunt. Russell Terriers originated from a terrier named Trump, who was supposed to breed a terrier that would have good stamina for hunting and courage to catch and chase foxes without actually hurting them. Another form of Russell Terriers were ones bred for badger digging. They were crossed with Bull Terriers to create a strong, small dog which were then described as Jack Russell Terriers.

There is controversy over the breed, as Jack Russell Terriers were not recognized by major dog registries for a long time. In 1990, Jack Russell Terriers were finally recognized. However, since recognition is still quite recent, there is still no kind of conformity on naming and classifying the different types of dogs yet.

Jack Russell Terriers are about 25 to 30 cm tall and are mostly white with various colors such as black or tan on the face and tail. Their ears are V-shaped and fold forward. Jack Russell Terriers have strong teeth and a dense double coat which comes in three varieties.

Jack Russell Terriers' tails, which are 6 to 8 inches long, are straight and upright. In the past, the tails were often cut short to about 4 inches, supposedly to give them a human hand's grip so hunters could help pull them out of holes. Fortunately, docking like this is now illegal and is less common.

An outgoing breed with a keen expression, Jack Russell Terriers are considered intelligent and are filled with energy. They are popular pets due to their small size, friendly nature, intelligence and curiosity. They need a lot of exercise as they have a hunting background and are meant to be strong and fast. Though they love to play, training is necessary as untrained Jack Russell Terriers tend to have difficult behaviors.

Jack Russell Terriers make good watchdogs as they were designed to bark at prey. Though they are very vocal dogs, they do not bark unless there is a good reason to. They are good with children, but any kind of abuse, even accidental, is not tolerated by them. Most Jack Russell Terriers are outgoing and friendly to other dogs, but some can be fairly aggressive. Jack Russell Terriers are also known as not being afraid of larger dogs, which can be a bad thing and lead to injuries.

Jack Russell Terriers, if taken care of, can live for over 15 years. The main health issue with them is cataracts, which is often seen in Jack Russell Terriers whose breeding stock is not tested.

Jack Russell Terriers are popular on screen as well, as they have vivid facial expressions and a feisty personality. Famous Jack Russell Terriers include Wishbone, who has his own television series, Milo from the popular comedy movie "The Mask" and Eddie, the popular dog on Frasier.

Jack Russell Terriers make great pets as they are small and friendly, yet also are attentive, strong and vocal when they need to be.