Right outside my back door I have a 20'x20' fenced in run for my house dogs (Two pitbulls) they have a doggie door to go out when they want. I also have enough fence to make it a 20' x 50' area. Would it be okay to use that as a run for chickens as well? I was thinking it would help keep predators out if the dogs were able to go out there. the dogs could careless about messin with the chickens and they dont seem to mind the dogs either.And would that be enough room for all 19 chickens?