[BK911]

Three dogs about 5 years old; a ridgeback and two German Sheppard/lab mixes.
About 300 lbs of dog!
I live in a pretty rural wooded area. Most homes are on 5+ acres.
I am on 20 acres, mostly wooded but about 1/2 acres of grass in the middle.
Until recently my pooches have had free run and were mostly staying out of trouble.
Not sure what happened, but we have started getting letters from animal control and neighbors about our dogs free roaming the area.
So now I have to find a way to keep them on my property.
I tried the system that plugs into the wall and emits a circular signal that provides a shock through the collar whenever the dog hits the boundary.
Knuckleheads ran right through it to chase a squirrel, but wouldn't come back in!! Several times!!!
Thinking of a direct buried system. Is this better?
What have you guys used that works on stubborn pooches?
Really don't want a physical fence, but will if that is what it takes.