Jack Russell’s are working terriers. They were first bred to chase fox from their dens while hunting and they are used to do the same with groundhogs and badgers. The Jack Russell is a very intelligent and fearless dog. If they are not properly exercised, they may become destructive when left alone. Same goes for many other dog breeds. They require a lot of exercise since they do have quite a bit of energy. Having such a high energy level, agility works best for them. They are a well balanced dog with very alert sences at all times.
The Jack Russell has a life expectancy of up to 18 yrs. They stay active well into their later years. Jack Russell’s average up to 15lbs in weight. While many Jack Russell Terriers are used for working dogs, if their chest is too broad they are unable to do any underground work which is what they are needed for. The smaller the better in this case.