Thanks everyone for your comforting words.
The vet suggested I give him Pepcid yesterday to see if maybe his tummy was upset and I can't believe this but it's helping! He ate almost 3oz yesterday. They get 6oz per day so that's a huge amount of food that he ate. And this morning he ate quite a bit too. So I'm quite hopeful at the moment.
If you can believe this I actually got his urine last night. The vet said to try putting a plastic bag in the litter pan so I locked him in the room (I was with him) and 10 minutes later he did his business. I can't believe he actually did it. Granted it was 11:15 last night and I was exhausted but hey, I got his pee!
I'll be really upset (and grateful
) if all this turns out to be an upset digestive tract! I'll get the results of his urine tomorrow morning. I'll keep you updated.