I had to put an electric fence (not an underground fence) up for a Jack Russell I used to have. I just borrowed the part that electrifies the wire. She got shocked once and stopped trying to climb out (then we had to move the wire to the bottom of the fence so she would stop trying to dig out). Then we gave back the thing that electrifies the wire.

I tried the underground fence with her, too (the kind that requires a collar). She thought that shock was WORTH IT to chase a cat or squirrel on the other side of the line. She wasn't willing to take the shock to come back, though!

Karen