Hey all, I have a dog in my class who is fond of leaping over a 5' high fence (he swears she does)

I have my own ideas as to what might work, but I wanted to see what everyone else might offer as a way to keep his golden from leaping over the fence.

A little background:
He rescued her a few months ago and she was basically chained in a yard her whole life til he got his hands on her. He will NOT chain her in the yard since he feels that since she was abused that way, he doesn't want to remind her of her past owners. She's 4 years old, spayed.

Thats about as much as I know right now since we haven't really gotten to talk much yet. He'll be in class in two weeks, so I have some time to figure out what to do to help him and his dog.

Thanks in advance for your ideas.