Everything poops. Especially dogs. Dogs are creatures of habit, whose training is ignored at the owner's peril. They want to eat, exercise, and poop at more or less the same times every day. When their regular feeder/walker/pooper-scooper is not available, they still want to eat, exercise, and poop on schedule. Unlike cats, they do not have a litter box inside. It is therefore of vital importance that their temporary feeder/walker/pooper-scooper keep to the schedule.