My dog runs away when off-leash. How do I stop him from escaping?

Hello and thank you for reaching out to Petco Pet Education Center, formerly Petcoach. It sounds like Toffee may not know his boundaries well, and assumes he can run everywhere once he's outside. I recommend training him on a leash to show him where his boundaries are. For example, walk him on a leash around the perimeter of your property, and never beyond. You can make him sit at the edge of your property, and give him a treat. Do this at multiple points around your property. Since he has run off before, he may not learn the true edge of his property. The safest thing to do is to take him out on a leash and not let him run freely. He is otherwise at risk of getting lost, or even hit by a vehicle. I hope this is helpful.