My 5-year-old Himalayan cat has just recently started to do the reverse sneezing thing. His latest episode was in August of this year, and I took him to both an ER vet and my regular vet when it happened. They both mentioned/thought it could be an upper respiratory infection. He didn't have any discharge from his nose, eyes, or anywhere else. He was playing and eating and drinking normally as well, still very affectionate, and not hiding. So really all he was doing was sneezing/reverse sneezing. I am not schooled much in the veterinarian field, so if anyone with experience or knowledge of this could give me some advice, I'd love it! He has an appointment with his regular vet tomorrow morning at 9:00 a.m. just to be safe.