Had the same with my 6-month-old staffie a few years back;
Went out to a gig and locked it in the kitchen (where it had it's bed) - came home and it'd butted the door into my fishing room off its latch and had eaten three trade packs of Mucilin (fly line floatant), plus a few cards of flies were mysteriously lacking in numbers too. Next morning, it was the only time I've seen dog poop setting rock-hard as it went from the warm interior of Dave (that's the dog) into freezin' cold mid-winter air. Mind you, it was easy to clean up - looked like those fake poops you get in joke shops
Never did find the flies though....
