[luvmyanimals]

I am not a cat owner but I do work with animals. Maybe you could do what Yme2 said, just for like a week or however long it takes, keep him in a big dog cage and keep his litter box and his favorite blanket and toy in it. Or block off part of a room so he only has a little room to go and make that HIS space, put his food and water, toys, blankets, and his litter box, and if you happen to catch him going in his litter box, give him something he loves like tuna or something. And in that area, put pee pads everywhere. And try putting his food and water next to his litter box. And like everyone else said, call your vet first, they will not only check to see if anythings wrong, they can give you advice if there is no problem on how to help Diego use his litter box. And I hope you guys can figure all of this out and you can keep Diego. Please keep us updated.

WE WILL KEEP YOU AND DIEGO IN OUR THOUGHTS!

-THERESA