Adie was such a good climber she even climbed up the back of the couch using her little toenails. (ouch!)
Anyway we solved the problem by going to Menards and buying plastic lattice. we just had to wedge it up against the door.
Lowes has them too.
Shop 4' x 8' White Plastic Lattice Panel at Lowes.com
Good luck! If Rucker is anything like Adie you are going to need it but you will also have the time of your life!