I hope you don't have raccoons, we have really big ones and they would have no problem getting into your run. They are the smartest little demons I have ever seen.
I have one that can fly up onto the top of my six foot fence and then over onto the outside of her enclosure. She will come back in just before it gets dark. None of the others can do this unless something scares them , So they can go over a four foot easily.
You need to check the laws in your area, where I live since they are livestock they will have to pay you more than the value of replacing them. It could be quite a bit of difference. I have heard some places value them as much as ten times what you would pay for them. This just happened to my...