I'm the barn owner... There is a 40 ft section of my fence that is just one rail pipe and it divides 2 pastures. We've had it like that for a year. We've had 3 horses go under it (14.2 and below) no injuries though.
A boarder's arab mare crawled under it into the other pasture with 2 other horses. After about 20 minutes her and another mother got into it and and the arab mare got a torn vulva.
The owner isn't mad or anything like that but another boarder mentioned she would've expected the barn owner to pay for it saying that it was negligence on my part for leaving the fence like that. I say it isn't because the boarder knew it was like that before she boarded her horse here. In fact, she asked about that particular part of the fence and we told her that yes horses have gotten under it before but it doesn't cause any injury and its infrequent. We also told her it was on our to-do list but wasn't a high priority.
Just curious what your opinion is..