The best wireless dog fences help keep your pups safe outdoors. We tapped a professional trainer to choose our top 4 picks.

Your pet wears an electronic collar that gives them a gentle shock every time they try to cross the line of the electric ... through the invisible barrier. Also, an invisible fence won't keep ...

The phrase "virtual fence" might evoke images of those invisible dog fences in backyards ... an electrical stimulus similar to one from an electric fence. Previous work on virtual cattle fences ...