Polyps removed surgically from a cat are adjacent to a cotton swab for size comparison. Photo courtesy of VIN.
Naso-pharyngeal polyps (nasopharyngeal polyps, otopharyngeal polyps, inflammatory polyps, middle ear polyps) are the most common masses that are seen in the external ear canal in cats. They are benign growths that can be seen in the back of the cat’s throat, the middle ear, and above the soft palate. Typically these polyps are seen in younger cats, although cats of any age can get them. There is no known breed or sex predilection.
No one is quite certain what causes naso-pharyngeal polyps. They may be caused by inflammation or a virus. Some cats that have these polyps also have feline calicivirus, and some cats have ear infections. Both of these problems can cause inflammation.
How an individual cat is affected depends on the location and size of the growth. Signs can include snoring, nasal discharge, sneezing, difficulty breathing, head shaking, balance problems, scratching at the ear, head tilt, nystagmus (an involuntary movement of both eyes in the same direction), bad odor from the ear, or an ear infection. If the polyp is large, the cat can have trouble swallowing, causing an owner to think the cat isn’t hungry.
Diagnostic tests include a physical examination, imaging (radiographs/CT/MRI) of the skull, and biopsy of the growth. If the ear is painful, cats may require sedation or anesthesia for the ear canal examination. If the cat is going to be sedated or anesthetized, that’s a perfect time in which to take radiographs of the skull. A biopsy may be necessary for a definitive diagnosis.
Polyps have to be removed surgically. Some polyps located at the back of the throat can be plucked out. This is a traction/avulsion technique. However, plucked growths often regrow. In some cases, a ventral bulla osteotomy may be used on aural polyps instead of the traction/avulsion technique. An e-collar may be necessary for 10 to 14 days after surgery to prevent the cat from disturbing the site. After surgery, the cat may be on antibiotics for a few weeks.
Depending on the location of the polyp, the surgery (and the polyp) may cause some side effects on the nerves around the eye. The cat may have difficulty blinking. Generally, the nerve damage will not last more than a few days or weeks, although permanent damage is possible.
Because the exact cause of each polyp is unknown, polyps sometimes recur after surgery. Some studies have shown that there is a recurrence rate of 15-50% after traction removal. Your veterinarian may advise the use prednisone for 2 weeks after traction removal, because it may reduce the incidence of recurrence. As with all diseases, the earlier a naso-pharyngeal polyp is diagnosed and treated, the better the prognosis.