There seems to be a sneezing issue running through my cats one by one. The first was having little sneezing fits, but no other issues--no runny eyes or nose, no labored breathing, eating, drinking, pooing all fine and normal. He sleeps a lot but he always does--it's more of a source of commentary if he's up a lot. He's a 9 yo neutered male. I thought it might be seasonal allergies. Then when his sneezing cleared up, the 1 yo neutered boy started with it. He *is* sleeping more than usual, but otherwise doesn't seem bothered. Now that his sneezing is lessening, the 10 mo girl is starting with it. Same thing--she's sleeping lots, but all else seems fine, except she's just gone into heat so she's acting a little funny from that (she's a stray we took in and until earlier this week, thought was pregnant already).

Any ideas? Allergies don't quite make sense, since they should all have them at the same time. A cold could, but there are no other symptoms and nobody seems generally poorly---if they did, I'd run them to the vet. I'm mostly just curious.