This is Azim. Azim likes to eat cat poop. Azim likes to eat cat poop in the yard. We decided to start using ground corn litter in out cat’s boxes as it’s better for their health. And we just adopted our 3rd cat who was a stray. We had to keep the bathroom door open so the cat would get use to using the box when he slept in the house at night. One morning we woke up, and all the litter was gone! We knew immediately that it was Azim. And he went from being a fit pit to being a fat one. Now, we have a door chain lock on the door so the dog won’t use his nose to open the door and the cat can slink in to use the box.
We had the same problem. I got a cat box with a lid and door. I turned it to face the wall with just enough room for the cats to get in but not the dog. Worked.
Same here, including the 10 lbs. Since I have many cats, there are many litter boxes. I’ve been Ikea hacking away to “secure” the boxes from the Diggers. Now Digby is on a diet and exercise regimen.
If your cats don’t mind a covered box, you may want to try a top opening litter box. You can hack them from storage totes with lids.