Well, they usually work well, not only at keeping your dogs in but also at keeping other things out. I'm guessing you need this for Bula, not for Dixie, in which case I'd suggest running two lines with two different currents. Run a low one on a dog current about 6 inches from the higher one. This will keep Dixie from getting into the higher one, and will keep Bula from figuring out how to shinny under the fence on her belly. Set the higher one - and you may actually need two strands on this one, one at about the level of Bula's front legs at about the elbow and another at her neck, back from the lowest one, and go to a farm supply store where you can get a charger that is solar powered. They don't carry quite the jolt of one that runs on AC current, but will still be a deterrent for Bula - which a dog charger probably wouldn't - and solar power is free. It's a strange phenomenon, but most dogs won't jump over an electric fence. Even Bimmer, who can easily clear ours, will walk all the way down the drive, through the gate and around the barn to avoid it. In a pinch, he'll hunker down and zoom underneath a high spot, but typically avoids the thing altogether. You should see Shiva and Kharma get those big butts low to get underneath!