Lol, it's like I'm reading about my dog.
What worked for me with litter boxes was turning them with the entrance of the litter box facing the wall. They're covered boxes, right?
If not, get covered ones. Then turn the litterbox with the entry hole facing the wall and move it close to the wall with only a tiny opening between the box and the wall. The cat will be able to get in, you know they can get anywhere but the dog can't.
Sent from Petguide.com Free App