I had two dogs who loved to eat my cat's poop. They had litter strewn all over the house. My boyfriend was at his wit's end. I went on the internet and found Purr-fect Privy, a litter containment system. http://www.pfprivy.com
It was a little expensive but I am here to tell you IT WORKS. My cat loved having her own private time back again. The dogs didn't even try anymore because they knew it was useless. Let me know if you have any questions. I'll be glad to answer them for you.