By Dr. Becker
Nasopharyngeal polyps are benign, protruding pink growths that develop in some cats at the back of the throat, in the middle ear, or above the soft palate. They are the most common growths seen in the external ear canal in cats.
Nasopharyngeal polyps typically occur in younger kitties, but any cat can acquire them regardless of age, breed or gender.
Causes and Symptoms of Nasopharyngeal Polyps
The exact cause of this type of polyp has yet to be confirmed, but according to Dr. James Flanders of Cornell University’s College of Veterinary Medicine:
“We believe that this type of polyp is caused by inflammatory changes secondary to infection with a respiratory virus. It might be a calicivirus, a herpesvirus, or any of the other types of viruses that cause sniffles in a young cat.
“The animal will be infected and will show the classic signs of upper respiratory distress. The signs will soon resolve, but some months later, the cat will start making this sneezing sort of noise and showing the other signs that a polyp has developed.”1
It seems during the months between initial symptom resolution and the onset of sneezing, the virus circulates through the cat’s system, traveling into the nose, mouth or middle ear. If it moves to the middle ear, the virus invades the tissue lining, causing inflammation, swelling, and eventually the formation of a polyp. Before long, the middle ear fills with inflammatory tissue, and the polyp can burst the eardrum.
Alternatively, the virus may pass into the nasopharanx, which is the empty area at the back of a cat’s mouth. Once there and anchored by a thin stalk, the polyp will continue to grow over a period of months until it begins to interfere with the kitty’s ability to breathe. That’s typically when the sneezing sounds begin. The cat senses there is something stuck in the back of his throat above the palate, and when he breathes through his nose, there’s a blockage that inhibits intake of air.
Sometimes the polyps form bilaterally, which makes them doubly dangerous if they grow large enough to block drainage from the nose.
Other symptoms, and how they affect a given cat, depend on the location and size of the mass. In addition to sneezing and difficulty breathing, other signs include noisy breathing, nasal discharge, snoring, head tilting or shaking, problems with balance, scratching at the ear, nystagmus (involuntary movement of the eyes), a foul smell from the ear, or an ear infection. If the polyp is large enough, it can interfere with a kitty’s ability to swallow, which can result in reluctance or refusal to eat.
Nasopharyngeal polyps can also cause symptoms of Horner's Syndrome, including a drooping eyelid, sunken eye, protruding third eyelid, or an abnormally small pupil.
Diagnosis and Treatment
If nasopharyngeal polyps are suspected, your cat will probably require sedation or anesthesia so your veterinarian can conduct a thorough examination of the palate and the nose, and also take tissue samples for biopsy.
Other tests may include x-rays, a CAT scan, or an MRI to look for lesions in the nasal cavity or nasopharanx. These tests can also be helpful in diagnosing other potential causes of your cat’s symptoms, including upper airway obstruction, a foreign body in the airway, a cancerous tumor, or a neurologic disease.
If nasopharyngeal polyps are found and are significantly affecting your cat’s quality of life, they must be removed surgically. It may be possible to simply pluck out a polyp located at the back at the throat. However, masses removed in this manner have a greater chance of recurring. Post-surgery, your kitty will probably need to wear an E-collar for 10 days to two weeks, and antibiotics are often prescribed.
Depending on the location of the polyp, both the mass and the surgery to remove it may affect the nerves around the eye. Your cat could have difficulty blinking, but usually this type of nerve damage resolves within a few days to a few weeks.
Nasopharyngeal polyps sometimes recur after surgery, and unfortunately, there’s no traditional way to prevent it. Some veterinarians prescribe oral steroids or eardrops to try to prevent recurrence, but those drugs – especially oral steroids – carry side effects that are not, in my opinion, worth the risk.
I have had some success in slowing down how quickly polyps return by nebulization therapy, which is having kitties inhale tiny droplets of aerosolized medicated salt water, which ends up being almost a topical therapy, as cats are nasal breathers. I use colloidal silver and Willard Water in the nebulization solution. I have also found that diffusing a very low concentration of the essential oil of eucalyptus in a cat’s living space can help reduce upper respiratory symptoms, as well. There are some homeopathics that may also be of benefit to cats with recurrent nasal polyps.
As with all diseases, the earlier nasopharyngeal polyps are diagnosed and treated, the better your cat’s prognosis for a full and hopefully permanent recovery.