You need to clean the mess of the dog before Yahtzee finds out.
Walk NORTH to enter the Yahtzeebrand General Store. You’re lucky day!, they’re selling poop scoopers. TALK TO CLERK to ask about the scooper. TAKE SCOOPER to get it from the shelf and go SOUTH to leave the shop and return to the dog.
To clean the mess you have to SCOOP DA POOP.
Game source: A copy of the game was found here on the internet.