I also stapled the hardware cloth1” bigger than the opening, then framed it in wood on top.Very sad. For our chicken run we used 4x4’s and 2x6’s with 1/4 inch hardware cloth. In addition we surrounded it with 2x4 welded wire. We have mountain lions, foxes, raccoons, gophers...you name it, as well as neighborhood dogs and nothing has gotten in. We also have feeding tubes that we seal every night. Hope you can rebuild and sorry for your loss.