I wonder if you have a possum? It made the neighbours dog really anxious, and his behaviour changed. Prior to this happening, he would poo in his "toilet" - a doggie bio loo - with no problems.
He has also started barking ALL NIGHT since the big wet. They are working on this, keeping the curtains slightly open where he can see them with my dressmakers dummy in the window!
We have used Poss Off from Bunnings where he was pooing, and it seems to have helped. Unfortunately, the possum poos and pees everywhere, and he just wants to send it a message. The possum at this point is winning . . ..