Carmen, the young rescue cat, seemed to have a cold. Her nose was running. She was sneezing. Otherwise, Carmen was fine — playful, hungry, and blessed with a sweet, affectionate nature. Assuming the upper respiratory infection would pass, a family adopted her. Carmen had already been spayed and received vaccinations prior to her adoption, so I didn’t meet her until six months later.
“She’s had this problem ever since we got her,” her owner explained. Carmen was sneezing violently, multiple times every day, often spraying mucousy discharge. They had learned to live with it, but recently her breathing had become more congested and the nasal discharge worse. When they noticed flecks of blood in the goo, they became concerned and called me.
Carmen was small, but a good weight and well hydrated. No fever. Tiny bits of discharge from both nostrils. Teeth? Clean, with no evidence of dental problems, but her gums were moderately inflamed. Referred snorting sounds from nasal congestion made it hard to auscult her heart and lungs, but what I could hear sounded normal.
Carmen had a condition commonly referred to as “snuffles.” A cute name for a seriously not-cute disease. The technical name is chronic rhinosinusitis. Rhino means nose. “Sinus” means, well, sinus; “itis” means inflammation. Thus the technical term merely describes the condition — ongoing inflammation of the nose and sinuses — but does not identify either cause or cure. There are many possible causes, but few cures.
It all starts with inflammation in the nose. Bacterial or fungal infections, viruses, foreign bodies, infected tooth roots, benign polyps, malignant tumors, allergies, nasal parasites, birth defects. All of these may be initiating causes for nasal inflammation. If a primary problem is quickly identified and can be eliminated, a true cure may be achieved. If not, the condition may progress. Secondary bacterial infections take hold in the damaged nasal lining. Inflammation spreads into the sinuses and honeycomb-like bones higher up, called turbinates. Chronic inflammation and infection erode the turbinate bones, causing irreversible structural damage.
Cats, especially rescue cats, have a very high incidence of feline herpesvirus-I (FHV-1) and calicivirus infections. These common upper respiratory viruses account for 90 percent of cases of acute feline rhinitis. It’s that classic sneezing kitten with runny eyes and nose and fever. Usually they get better in a week or two. They often remain chronic carriers, and may occasionally relapse, but few develop chronic snuffling like Carmen.
“Let’s rule out underlying immunosuppressive diseases like feline leukemia or feline immunodeficiency virus,” I said. She had been tested for both when first rescued, but sometimes initial tests give false negatives during early stages of infection. A quick retest happily ruled these out. Carmen’s nasal discharge was bilateral, i.e. from both nostrils. This made a foreign body a less likely diagnosis. Foreign bodies tend to be one-sided, like when a cat inhales a bit of grass. Carmen’s young age made tumor or polyp less likely. Those are usually found in older cats. Her gum inflammation was suggestive of chronic FHV-1 or calicivirus infection. All these facts, plus her early history as a rescue, gave us our presumptive diagnosis. Viral-induced chronic rhinosinusitis with secondary bacterial infection. If it walks like a duck and it sneezes like a duck …
Definitive diagnosis of underlying causes in snufflers is difficult. It’s impossible to get a good look up of those tiny noses without special equipment. Radiographs are sometimes helpful, but have serious limitations. Foreign bodies often aren’t visible, and increased density in nasal passages doesn’t differentiate infection between tumor and polyp on an X-ray. The optimum diagnostic tool is usually rhinoscopy performed under anesthesia by a specialist. A teeny-tiny fiberoptic scope passed up her nose allows the specialist to visualize the entire area, biopsy anything suspicious, culture if indicated, even remove foreign bodies if any are found.
Why don’t we just culture the goo Carmen sneezes out on the exam table? That’s like culturing a garbage can. On rare occasions, it may give useful information, but many kinds of bacteria, and even fungi, are routinely found in nasal discharge from perfectly healthy cats. Just because something grows on a culture doesn’t mean it’s the source of the problem. Testing for viruses is even more complicated, so we often simply assume a cat has been exposed. Even with referral and aggressive diagnostics, we frequently end up with the extremely frustrating diagnosis of idiopathic chronic rhinosinusitis. That means no specific initiating cause can be found. In one study reviewing 75 cases of cats with chronic nasal discharge, definitive cause was found in barely one-third of cases.
Carmen’s owners opted for empirical treatment rather than referral. I prescribed antibiotics. If antibiotic therapy fails to resolve snuffles in a week or two, then bacterial infection is not the primary issue. (If there is a response, six to eight weeks of continued treatment is advised.) For upper respiratory viruses, I prescribed oral lysine, which may help reduce replication of feline herpesvirus. For inflammation, a cat-safe, nonsteroidal anti-inflammatory. Three weeks later, Carmen’s meow was less hoarse. She was sneezing a bit less but, overall, was not significantly better.
“I believe the chronic infection has permanently damaged her nasal turbinates,” I sighed. This change in anatomy leaves affected cats prone to lifelong problems. Antibiotics may help, but not cure. Since active viral infection may no longer be implicated, antiviral medications are also not the answer. I proposed trying prednisolone, a corticosteroid. Using corticosteroids has some potential risks, but also many potential benefits. Prednisolone is a potent anti-inflammatory, inexpensive, and generally well-tolerated by cats.
Carmen did indeed respond very well to prednisolone. Her congestion and sneezing lessened significantly. We will slowly wean down to the lowest effective dose, maybe even be able to stop completely, only reinstituting medication periodically when symptoms recur.
Carmen is lucky. Her family adore her, and are willing to live with her frustrating chronic condition. She will never be cured, but we can focus on controlling her symptoms and improving quality of life for both her and her owners. Gesundheit.
