If it is necessary for a horse event and a non-horse event to be held simultaneously then each event must be made safe from the other and neither event must pose an additional risk to the participants of the other. Spectators must be protected from loose horses and runaway horses. The non-horse event participants and its spectators must be protected from the effects of the horse event or activities. The easiest method of protecting everybody is to fence off the non-horse activity, leaving pedestrian gates and larger gates if necessary. While some horses can jump even a five-foot fence, it is not likely, especially with a rider on top who is trying to avoid the fence and stop the horse altogether.
Horses have difficulty jumping big fences if the rider is set against it.
A five-foot fence or panel certainly satisfies the industry standard for safe horse fencing. It is essential that the non-horse activity be located in a reasonable place away from the main horse activity. This type of location poses a grave risk for the riders, as well as in this instance there would be a serious obstacle between the horses and the stable which is not normally there. This situation could result in serious liability to the facility as well as to the management of the non-horse activity depending to which group the victim belonged. Spectators at most horse activities assume the risk of injury due to accidents caused by horses being horses and for unusual incidents of play or competition.