Oh Jon, that poor PussPuss! There's not a lot you can do, as you say, except feeding and giving him water (Isn't this drought appalling?)
The bloating could be an enlarged liver, it's what our stray 'Solo' had. So kind of you to keep an eye on him.

I had to laugh about Furball's reaction to your playing.
I often play songs on Youtube on my laptop, and sing along. It really puzzles out two, and they stare right into my eyes as if to say, "What's the matter? Why are you howling like that? Shut up will you!"