Was there any change in Houdini's life a year ago that may have caused him to start peeing outside the litter box? Construction? move?
Is there a particular time of day that he pees outside the litterbox. Is there any correspondence to the time he also defecates (ie just defecated in his litter box so he won't go pee in it)?
Is his litter box located close to a noisy appliance? furnace?
Do you have two types of litter boxes (hooded/open)? Is he a big cat and is his litter box big enough for him?
Are you sure there are no kitty visitors that are coming into your area at night?
Cat maid to:
Puddles, female Himalayan (16 yrs)
Jasper, male Ragdoll ?? (approx 9 yrs)
Sweet Pea, female silver tabby DSH (approx 7 yrs)
Rose semi feral, a cpietra rescue, female tabby (approx 6 yrs)
Snowball RIP (1991-2005)
In a cat's eye, all things belong to cats.-English Proverb
“While we are free to choose our actions, we are not free to choose the consequences of our actions.” Stephen R. Covey