I have five hens and unfortunately, since so many people in my neighborhood let there dogs run loose without a leash, I can't let my chickens free range a lot for their safety, they have a big enough run with 15 sq ft per chicken, I try to let them have supervised free ranging as much as possible. Recently though, they have been jumping over the fence into my horses pasture and hanging out with her. She doesn't seem to mind having the chickens around her and the chickens can't stop going in. I'm concerned that she may injure them though. Any advice?