A couple of weeks ago I noticed that my normally slender male neutered cat had a swollen belly that feels hard not squishy. I waited a few days to see if it went away prior to taking him to the vet to see if maybe he was just constipated. His behavior has not changed; still eats, drinks water, allows me to rub his belly and hold him, shows no discomfort at all. Took him to the vet for a check; no fever, no sign of worms (although they did deworm him), no signs of stomach distension or tumors/lumps, etc. They aspirated to see if there was fluid, and it only appeared to be air. The vet suggested to wait a week to see if any change... and there has been none. The ONLY thing I can think of is I changed his dry food, but he didn't seem to overly eat. I've since gone back to the 'old' food the past week. Has anyone else had a similar situation?