From the picture the run is plenty wide for a dog to get in and the fence isn't that high. My alpacas can turn around in a space narrower than that and they are way bigger than a dog. And the fence, if it wasn't like that before, could have easily been bent over by a dog going in. At our prior house the neighbor had a black lab that would bend my 3' welded wire fence when it went over (which was often).No offense, but my run is not that wide. I don’t think a dog could’ve done that.
I ASSUME that dogs can get into that part of the yard? The wood fence we can see in the picture looks quite substantial and would likely keep a dog out.