Oh, I'm going to vote for poop, too. We had the hardest time keeping my big collie mix, Oasis out of the litter boxes. We bought the domed ones, but he'd still stick his head in there and then get it stuck so we'd come home and find it dragged half way across the floor because he'd be backing up and shaking his head to try to get back out.
We tried putting them in the garage with a kitty door for access, but the big old things managed to either squeeze through the door or make themselves a BIGGER hole by eating the door.
We actually secretly taped our aussie going into the garage at night. We had the litter box up on an old microwave cart. He stood up, pawed at the litter box a little to move it toward the edge, took a quick, guilty look at the door to the garage to make sure no one was coming, pawed at the box again, quick look at the door then knocked the box off the cart and had his midnight snack. It's HILARIOUS to watch - and great evidence for ANYONE who says dogs don't have a conscience!!
