Jack Russell Terrier

Gemma Gaitskell
Dr Gemma Gaitskell (BVetMed MSc MRCVS, Royal Veterinary College, London)
Photo of adult Jack Russell Terrier

Jack Russell Terriers are small, intelligent, strong dogs that come from working stock. They were originally bred to hunt and flush animals, in particular foxes from their dens. Today they are popular companions and make excellent farm and country dogs, preferring an active and stimulating environment. They have a compact appearance despite their small size and are hardy and athletic. They may have a variety of different types of coat, all easy to care for, of predominantly white in colour with various markings permitted.

The Jack Russell is of a friendly temperament and should not be aggressive but can have a strong character, which means training and socialisation is essential. A dog that is quick to learn and gets bored easily, the Jack Russell requires an active lifestyle and plenty of mental stimulation. Its hunting roots can mean the Jack Russell is prone to chasing other animals so obedience training is important. As a breed which descends from working stock they have few hereditary health problems.

About & History

Jack Russell Terriers were originally bred from a specific line of Fox Terriers in England toward the beginning of the 1800s. They were used as earth dogs to flush foxes, rabbits and other animals from their dens during hunts. Reverend John Russell, who gave it its name, developed the breed. By the mid 1800s the Jack Russell Terrier had begun to be recognised as a breed of its own. Although the Jack Russell originated in England the breed was then developed in Australia.

The breed should not be confused with the Parson Russell Terrier (formally known as the Parson Jack Russell Terrier), which is similar in appearance but with a taller stature and longer legs. Both breeds were developed from the same origins but played different roles within the hunt.

Unlike other breeds the Jack Russell registry has largely been run independently of the Kennel Club, although in 2015 the UK Kennel Club began to recognize the breed. The American Kennel Club also only began to recognise the breed in 2011 and the Jack Russell is known as the ‘Russell Terrier’. Breed registers have been kept ‘open’ and line breeding has been restricted with registration as adults as opposed to at birth, to try and maintain the desired working and functional characteristics. More recently Jack Russell Terriers have become popular companion dogs and are also used for flyball and agility due to their energetic nature.


Jack Russell Terrier Large Photo

Jack Russell terriers were originally mostly white, to help ensure they were easy to spot during the hunt, but several different markings are permitted. Other solid colours, apart from white with markings are not recognized by the UK Kennel Club. Acceptable markings can vary between the Kennel Clubs of different countries.

  • White
  • White with Black Markings
  • White with Black/Tan Markings
  • White with Tan Markings

It is acceptable for the coat to be smooth, broken or rough and it should also be weather resistant with both an undercoat and strong outer coat. The ideal height ranges from 25-30cm (10-12 inches) at the withers and weight should be proportionate to height, with approximately 1kg in weight for every 5cm in height.

The Jack Russell should be flexible and have an overall rectangular outline, with a body which is longer than its height. The legs should not be too short, ensuring space between the chest and the ground and legs should be the same length as the depth of the body. It is also important that the chest should not be overly wide as this would have prevented the Jack Russell performing its work and going to ground.

Ears should be small and V-shaped button or drop ears which show a lot of expression. Eyes should be deep and dark with an almond shape and should show an intense alert expression. The rims of the eyelids should be black and pigmented. The mouth should be strong and powerful with black lips, large teeth and a scissor bite. Any dogs with faults in jaw alignment should not be used for breeding. The nose should also be completely black and pigmented.

Movement should be natural, active and free and the Jack Russell should have a spring in its step showing a confident gait.

The appearance of the Jack Russell Terrier is built around its ability to perform as a working dog and the development of any accentuated or unbalanced characteristics which could interfere with this ability are considered undesirable. Any signs of achondroplasia (a genetic mutation associated with dwarfism) are seen as a severe fault in the breed.

Breed differences between countries are mainly to do with the height and size of the dog.

Character & Temperament

Jack Russell’s should be alert and lively with an inquisitive nature. They are renowned for their fearless character but should not be aggressive or at the other end of the spectrum, nervous with people. These are friendly dogs, which are generally good with children if children are taught to respect them, but they will not tolerate lots of prodding and poking. Despite their usually friendly nature it is important to socialise and train them from a young age otherwise they can be antisocial with other dogs.

They are confident and have endless energy and are happiest in an active household, with plenty of exercise be it in the city or countryside. Due to their energetic and intelligent nature Jack Russell’s can become destructive or naughty with a tendency to bark if there is insufficient stimulation in their life, leading to boredom.

Although the Jack Russell is a small dog they are intensely loyal and this means they will attempt to guard their household, although their size is a limitation to their ability to act as a convincing guard dog. Due to their loyal nature Jack Russell’s prefer to have company, however, if properly managed from puppyhood most dogs can be trained to be left alone without suffering separation anxiety. Ideally time alone should be kept to a minimum, but good training is key to preventing problems later on in life.


Photo of Jack Russell Terrier puppy

Jack Russell Terriers are highly trainable due to their intelligent nature and can be taught numerous tricks, however they can also be independent and prone to distraction. Sufficient exercise and mental stimulation are the keys to ensuring they are focused and interested in their training.

Once trained Jack Russell’s can be very obedient but due to their hunting roots can be prone to chasing other animals, which can make recall a problem in certain situations. It is important to start training from a young age as they can be stubborn and bad habits are difficult to resolve. Some problem behaviours, which Jack Russell’s are prone to if not properly managed, include digging, chewing and barking.

Due to its large personality and lively character this is a breed which is recommended only for dog owners with experience as it can be difficult to manage. It needs discipline and training to get the best out of it and flourish as a companion. The quick to learn intelligent nature of the Jack Russell means that house-training is generally not a problem and once a routine is established puppies prefer not to have to soil the house.


Jack Russell Terriers are generally a healthy breed with few problems, partly due to their working nature and function being favoured over form and the fact that direct in-line breeding has not been permitted. They have a fairly long life expectancy of between 13-16 years.

Jack Russell Terriers are not prone to welfare problems caused by their conformation. However, despite this there are some lines which carry hereditary disorders, although these are uncommon and not mentioned on the Kennel Club’s watch list. Some of these problems include:

Patellar Luxation

A condition where the equivalent joint to the human knee in the hind leg is affected, with the patella or kneecap becoming temporarily displaced. The condition can vary in severity with one or both legs being affected and can be corrected if necessary by surgery.

Primary Lens Luxation (PLL)

Where the lens in one or both eyes is displaced, either forwards or backwards in relation to its normal position. This can go on to cause secondary glaucoma and blindness. If diagnosed soon enough the condition can be treated and additional complications prevented. Genetic testing is available to detect carriers and determine whether a dog is affected before clinical signs develop. The condition usually develops between 3-6 years of age.

Legg-Calvé-Perthes Disease

A disease that affects the hip joint because the head of the femur suffers from a reduced blood supply causing the bone to become necrotic and die. This means the bone no longer fits into the hip socket correctly and causes stiffness and pain. If a dog is affected the condition often develops between 4 months and a year of age.

Herditary Ataxia

An axonopathy (where the axons of nerve fibres are affected) of the central nervous system which causes a loss of coordination and exaggerated movements as well as seizures in some cases. If a dog suffers from this disease signs are usually seen around 2-6 months of age.

Exercise and Activity Levels

Jack Russell Terriers are extremely energetic and active little dogs. They have been bred for stamina so take a lot of exercise to get tired. Jack Russell’s can keep going all day and are therefore popular farm and country dogs which enjoy adventure. They require a minimum of one to two hours exercise a day and this should ideally include some time off the lead.


The Jack Russell is has a low maintenance coat and requires minimal grooming. Occasional brushing at home to prevent any shedding in the house is sufficient. Due to the emphasis in their breeding for a working dog they are not prone to ear infections. Baths are only needed very rarely.

Famous Jack Russell Terriers

Due to their intelligent and quick to learn nature there are numerous well known Jack Russell’s and examples in popular culture. Some famous Jack Russell Terriers include:

  • Jack from the film, The Artist
  • Milo from the film, The Mask
  • Skip from the film, My Dog Skip
  • Arthur from the film, Beginners
  • Baby from the film, Clean Slate
  • Chalky, owned by the famous chef, Rick Stein
  • Eddie from the American sitcom, Frasier
  • Nipper the dog in the painting, His Master’s Voice by Francis Barraud (maintained to this day in the HMV logo)
  • Bothy, belonged to explorer, Sir Ranulph Fiennes, and travelled to the north and south poles with him


Popular Jack Russell crossbreeds today include:

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