Jack Russell Terriers may be small - but like the much larger Malamutes and Boerboels, they are working dogs, and so need their daily quota of exercise. Keeping these little dogs happy is key to ensuring a harmonious household.
Many people mistakenly choose them as pets because of their small size, innate intelligence, and friendly, playful nature. They imagine the dog will be a facsimile of Eddie, in Frasier.
But the agile antics of a Jack Russell that is not schooled or exercised properly will in reality resemble more those of Milo in The Mask; soiling carpets, chewing soft furnishings, digging up plants, biting and nipping. This is not a two-walks a day dog. As the adage goes, when it is good it is very good, but when it is bad, it is horrid.
Although they are reputedly good with children, they do not take kindly to abuse - even if it is the usual unintentional provocation of prodding or tail-pulling. They have been known to bite children who tease them once too often. For this reason, these little dogs are not generally recommended in homes where small children are present.
These dogs, when deprived of their right, become fidgety to the point of being called "hyperactive" or "excitable." Moreover, Jack Russell terriers are by nature voluble. When they lack exercise, they become even more so - as well as aggressive and potentially vicious.
They are a cross between the original Russell Terriers, bred for fox hunting, or badger digging, and Bull Terriers. This may explain why they were only recognized as a breed proper fairly recently, in 1989.
Exercising a Jack Russell Terrier must be an energetic pursuit; he must be allowed to run freely, and preferably chase-and-fetch something, be it a ball, a Frisbee, or a stick, to bring to the fore his instinctive behavior without allowing him to damage property or harm people.
However, on walks the dog must be kept on a leash since it will chase anything that moves.
At the very least, a Jack Russell Terrier requires 45 minutes a day of vigorous exercise - it has the stamina to stand two straight hours of strenuous working out. It is not afraid to challenge breeds twice its size; this may also lead to serious injuries. On the other hand, it tends to be aggressive towards other Jack Russell Terriers, and animals that are smaller in size.
One must constantly treat a Jack Russell as a big dog with a small body; an intelligent, cunning dog that knows what it wants and will attempt to get it. But if he is taught that he is not the Alpha Dog in the home, he will accommodate the person who is.