My sister-in-law had a problem with her dog jumping the fence; she found a "jump harness" on the internet, but never bought one. Her dog is a big baby and the electrified wire worked for him, lol! But here's the link, if you are interested:
No Jump Harness - Dog Harnesses at Arcata Pet Supplies
I have no idea if these things work, if they harm the dog, etc. I don't know anyone who has ever used one; but maybe someone here does, or you can find more info with a google search.