I sneeze from time to time because we're getting leaves blow off trees here and that produces allergy stuff in the air and will make me sneeze every so often. Both my cats will sneeze every so often and their eyes will run a bit. All three of us has a touch of allergy from time to time and the vet checked that out for them. Sometimes, if you check the allergy reports online, you'll find the pollen is at a higher level or the trees are higher and it can give you an idea of what sets them off.

I noticed we also get sneezing when I turn the heat on. I use a vaporizer, but the heat always seems to do it for all three of us.

Yes, I would guess that the heat is the culprit! The other cat obviously is not bothered by it.

KK

Yes it could be the heat, but the other cat isn't sneezing. But that could still be the culprit...the heat. I hope he stops sneezing soon, other wise he seems to be ok just a little tired more since he's been sneezing. I f he doesn't do better soon, in a few days I'll check with the vet.
Thank you both.

My one cat went into the vet on Friday and he has some stuff in his sinuses under his eyes. So he was put on childrens Benedryl liquid and it is suspected it is allergies.

Well one cat stopped sneezing and now the other cat is sneezing...I still think its the heat or an allergy. They are still playing just fine and being their happy selves.
And wow...I didn't know cats could take Benedryl of any kind.

Not sure if your kitties are indoor only or if you adopted them from a shelter but they could have still been born with the herpes virus. You wouldn't even know it until they had a flare up with runny eyes and sneezing. Anyway my feral cats have it and I give them L-lysine every day in the canned food I feed them. If given every day you can prevent a bad flare up. I used to only give it to them when they had a flare up but I leaned if given every day it can prevent the flare ups in the first place. You can just get it from a health food store. They have not had a flare up since I started giving every day. The L-lysine works well for kitty colds as well.

Our kitties are indoor only, we adopted them from a shelter one year ago today. They were tested for different diseases when we first got them and the vet said they were healthy. But if the sneezing cont I will give the L-lysine a try.
Thanks