The dog exercise pen just isn't stable meaning very study as.
I am afraid a predator could just push the run as is now, does everyone think this exercise pen would be as strong as Welded Wire Mesh?
These are hard word floor that is pieced together making up this coop, so not sure what i would use to cut a door or a ventilation on the side.
So using Mesh Hardware Cloth on the top and side of this pen with nothing else should work fine against outside predators.
We plan on growing grapes all over the run to make it cool in the summer for good shade.
My puppies could move and re-shape their exercise pen, like your. I think you need to put in some steel fence post at joints to anchor it. You can drill large holes in 2 diagonal corners and then use a jig saw to cut out the chicken door and for ventilation. If you put the hinges on top of chicken door, it can work as a rain awning when open.