[jakes mom]

Akari, maybe he’s just not a chicken kind of guy? Try turkey?
I agree with Bobby dog, if the litter box habits have changed, that’s troubling. On average the clumps in my cat’s boxes are 2-3 inches. Fist sized sounds large to me.
As far as getting him to drink more, my 5 like clam juice and canned clams in broth. Clams are naturally salty so maybe that will make him thirsty,too.