How to get the dogs to stop using the bathroom on the porch?

I just made a yard for mine, all other doors locked for pets. they have to use a pet door. but there food bowls and toys are in the yard to. next to their door is a sim door, so my sims don't have to go all the way around the house to get to the dogs. But my sims have their own porch where they eat now, without dog mess.