I worked at a dog kennel and they had small wires on top of the fences to dissuade them from going over. Obviously, it had to be tested. It was like a 9volt battery to the body. It guess one could describe it as painful but I found it more weird than anything. 7/10 did it several times.

Interestingly, the people who owned the kennel also raised horses. That fence I touched on accident and it absolutely sucked. Parts of me were also numb for almost a minute. 1/10 do not recommend