I had a rescued Wolf hybrid  that was impossible to keep fenced in' I solved the problem with a steel cable overhead that gave him plenty of room to run and since it was above his shelter and water he was safe and secure and tangle free..ONCE I got a body harness on him..he could slip out of any neck collar I owned..only good for about 48 hours as the son of a gun would start to chew the the rubber coated steel cable after that. I actually ran a double cable to harness which kept him safe and every living creature in his range safe.