My 12-year-old cat, Buddy, has a constantly stuffed-up and runny nose. He sneezes regularly, sometimes having what I call sneeze attacks, where he sneezes repeatedly over and over and spraying mucous out of his nose. The mucous is sometimes orange, sometimes clear. My cat has been given Lysine chews, which he ate for a while and now won’t touch. He has had antibiotics, which did nothing. His previous owner had him for the last 9 years and adopted him out of a shelter. She said that no vet she’d ever taken Buddy to could figure out his sinus problem. My vet didn’t know why he would have this condition either.
He is perfectly healthy in every other respect, but the constant sniffling, runny nose and sneezing situation can’t be pleasant for him.
It sounds like your cat has chronic sinusitis. This usually results from a severe prior respiratory infection. Many kittens get a viral respiratory infection from shelters, with the herpesvirus being the most likely culprit. The kitten recovers, but in severe cases the infection results in damage to the delicate turbinate bones in the nasal cavity. This compromises the ability of the respiratory immune system to fight off infection, and cats end up with chronic sinusitis.
No consistently effective treatment exists for this. During flare-ups, antibiotics may help reduce some of the clinical signs, but the cat will always have a low level of nasal discharge and congestion. Very severe flare-ups may respond to anti-inflammatory drugs like corticosteroids. Lysine is an amino acid that is often effective for recurrent flare-ups of herpesvirus infection, but this is not quite what is going on with your cat. Cats with recurrent herpesvirus flare-ups will go through periods where they are normal, and then a period where they have signs of an upper respiratory tract infection.
Your cat doesn’t go through “normal” periods. Your cat always has a low level of snuffles and congestion. Lysine is less likely to help in these cases. Famciclovir is an anti-viral drug that might be worth a try. It works best for cases of recurrent herpesvirus infections, but I have had a few cases of chronic sinusitis that did respond to a month-long course of this drug. Be forewarned, however, that this drug is expensive. I wouldn’t worry about your cat too much, though. This constant congestion is the only life he’s ever known, so he probably doesn’t even realize that this is abnormal. To him, this is the way life is supposed to be. Chronic sinusitis has no effect on lifespan, so despite the sneezing and snuffling, Buddy will probably live a long, happy life.