I know it will sound like the last thing you need or want, but have you considered another puppy or kitten? The adjustment takes a little while, but once they bond there is a friend there all the time. I know for me, thats always been the case. If I ever have to leave one home alone, for the vet etc..the other one is miserable. I really noticed in January when I had to let my dog go. His brother who is well house trained, started to go in the house. He was so anxious and depressed. I have been told not to assign human emotions to my pets, but I know what I see is the doggy version. When I got the new puppy, Harry was not happy at all, lol. BUT, he's occupied with her and its giving him something else to focus on. No more accidents (on purposes) lol. In fact, I think he's been the most helpful in getting the puppy on board with potty training. Just a thought. I have always had multiple pets at the same time. I'm also the mother of human triplets, lol. For me one of anything isn't enough it seems