I had the same problem and took SamK's advice and it really helped me. A year later, my dog stopped jumping over the fence and we removed the collar. However, at first I was suspicious of such a collar, as I did not want the dog to be hurt. I searched in Yahoo and found this article https://thepetsmaster.com/best-wireless-dog-fences/ which describes in detail how everything works. I also learned that a strong electric shock doesn't occur and the dog will be fine. Now I recommend the shock collar, as it is effective and cheaper than using the services of a dog trainer.