Physical characteristicsThe Jack Russell Terrier (JRT) is a compact dog with a sturdy and well-balanced build. The head is in proportion to the body, with a defined stop. The nose is black. The dark almond-shaped eyes are full of life and intelligence. The small V-shaped ears are pendent and carried forward close to the head. The jaws are powerful and well-boned with the teeth meeting in a scissor (preferred) or level bite. The chest is shallow and narrow. The hindquarters are strong and muscular. The tail is set rather high; it is in proportion to the body length, usually about four inches long. The gait is free, lively, and well-coordinated.
Jack Russell Terriers weigh 14 to 18 pounds. Their height is 10 to 15 inches at the withers.
TemperamentWhile very adaptable to a lot of environments, JRTs are first and foremost bred to be hunting dogs. City or apartment living, as well as a confined or sedate lifestyle, don't quite meet their needs. These little dogs require an extraordinary amount of human attention, outdoor activity, exercise, discipline and acceptance of their hunting nature. If they are not properly stimulated and exercised, Jack Russells may become moody and destructive. They have a tendency to bore easily, and will often create their own fun when left alone for too long a time.
Special facilities are absolutely necessary with a Jack Russell, especially when you have two or more dogs. Remember that their natural hunting instinct brings out aggression towards other small animals such as cats, gerbils, guinea pigs, etc. Jack Russells can be very aggressive towards other dogs, too. Firm leadership, obedience training, discipline and proper socialization are required at an early age. A stable Jack Russell can make a terrific family pet. Usually, these dogs get along well with well-behaved children.
Coat and groomingThere are three varieties of JRTs: rough, smooth, and broken. A smooth-coated JRT should have smooth coat all over the body, with a dense topcoat that is approximately 1 cm long. A rough-coated JRT should have a rough double coat up to 10 cm long. A broken-coated JRT has a topcoat of intermediate length, or partially smooth coat with longer hair on some parts of the body (usually on the tail and face). The rough variety requires more frequent grooming than the smooth one.
Regardless of the coat type, JRTs come in prevailing white colour (51% or more) with some tan and black markings.
HealthJRTs are naturally healthy and robust. Some lines, however, may be prone to hereditary cataracts, ectopia lentis (lens luxation), congenital deafness, patellar luxation, ataxia, and myasthenia gravis.
The lifespan is relatively long - 13 to 16 years.
Other interesting factsThe name "Jack Russell" has been used to describe a wide array of small white terriers, but is now most commonly used to describe a working terrier.
The Jack Russell Terrier is not the same as the Parson Russell Terrier. These two breeds are similar because they share a common origin, but there are several marked differences. The most notable is the range of acceptable heights. Other differences in the Parson include a longer head and larger chest as well as a larger body size. The Parson Russell is a conformation show standard whereas the Jack Russell standard is a more general working standard.