Here's our experience. We started with a two foot fence, and Roxi just hopped over it no problem. So we put in a 4 footer and she would jump up as high as she could and "grab" on to the fence and then climb the rest of the way over. She does the same with baby gates in the house. If we want to keep her contained we stack 3 in the door way so they reach almost the top of the door. If he is a jumper and a climber, I'm thinking privacy fence.
