We have Invisible Fence for our dogs, and Buddy was the eighth dog that we had with it. He decided that killing chickens was worth running through it! We tried everything that IF had, and it wasn't enough. So, the Ft. Knox dog fence. It's either chain link or 2"x4" woven wire, or 4"x4" woven wire, topped by electric tape, and with the IF effective three feet inside, so dogs don't get to the fence at all. Overkill, maybe, but Buddy never got out again, and since then no other dog has escaped either!
Sadly, it's also made me lazy, so current dogs are NOT chicken safe. They are fenced.
Mary