I hope there's nothing serious wrong with gorgeous Tigris.

It sounds like a good idea to have his tummy checked, though. Have you tried giving him a mix of Hills W/D-S/D? That helped Fister - although recently, he has had Royal Canin's S/O, which also seems to be good for him.

Sending lots of good wishes for a succesful vet visit - and kisses to Tigris.