Keep Your Jack Russell on a Leash at All Times
It's always advisable to keep your Jack Russell on a leash when out in the public or in wilderness areas you are unfamiliar with. If the dog is loose and catches an interesting scent he will be gone. Jack Russell's seem to suffer from an indefinable, genetic form of deafness, known to people as selective hearing. They appear to hear very well any other time, but when they've caught an interesting scent all your cries of "stop!" and "come back here!" seem to go unheard. It's wise to keep your Jack on a leash in public parks. Jack Russell's don't only see foxes, cats, raccoons and other furry animals as an enemy. Jack Russell's have also been known to aggressively attack, defend against, and hunt any digging or crawling animal, even snakes.
As previously stated, Jack Russell's do not possess the fears that humans do. A Jack Russell will respond to an aggressive snake in the same way as an aggressive dog, and even chase them to their holes and dig if need be to catch them. Many Jack Russell's have met an untimely end from a poisonous snake. It's recommended to never leave your dog unattended in a place where it may encounter such an animal. If possible it's best to avoid any type of snake altogether. Although a Jack Russell can and will easily kill snakes, poisonous or not; non-poisonous snakes can still present a danger. Some species of non-poisonous snakes will have long, hooked fangs and will bite your dog in self defense. If these bites become infected they are not treatable on the surface because the infection is actually nowhere near the puncture wound. These types of infected wounds can result in fatal blood poisoning or painful and expensive surgery. It is best to simply avoid snakes altogether.