I have a filly who not only climbs fences, she CRAWLS under them! She was seen belly crawling to get under the fence so she could go graze. She can't be kept in cattle panels (she climbs them), nor can she be kept in regular panels (she crawls under them). So I had to send her back to our family farm, which is fenced in 4 foot predator fence (welded wire horse fence). So far so good, no climbing on that fence! Which is good, because we had two barbed wire lines run above it, as we've had issues with dogs getting into our pastures before. The combination seems to have worked, our only issues now is people climbing over the fence to cut across our pasture. We've even had the kids next door cut part of it. And those two days someone opened our gates (once letting the mares out almost onto the road, and the other letting the colts in with the girls... oh JOY! 2 possible fall births).