That second photo should work, not sure what's going on with that first photo. My concern is that a critter could force itself under the fence if there is a gap between the bottom of the fence and the apron.
Could you show a photo of how your apron is connected to the bottom of your run. The apron and fence should not have a gap that a fox can get through. If a fox can get through so can many other critters. Before I comment too much I'd like to see what you have.
I agree about your dog. She...