Nasopharyngeal Polyps

What are nasopharyngeal polyps?

Polyps are a benign form of growth – meaning they do not spread from one part of the body to another.  Nasopharyngeal polyps arise in the middle ear, the compartment just behind the ear-drum.  As they become larger they grow down the auditory canal (Eustachian tube) which is the tube that connects the middle ear to back of the throat.  The polyp expands, filling and blocking the cavity at the back of the mouth and nose.  The main effect of the polyp is to interfere with nasal breathing and affected cats usually develop a distinctive snorting sound as they breathe.  Cats are not good mouth breathers and will struggle to breath through their obstructed nose often convincing the owner that they are choking.  Whilst this type of breathing in your cat is unpleasant to watch it is usually not life threatening but does require veterinary attention.  Secondary bacterial infection can develop due to the blockage and accumulation of secretions and this may result in a discharge from the nose and sneezing.

The cause of polyps is not known.  It is thought that they may result as a response to chronic inflammation as they commonly develop after “cat flu” or respiratory infections.  Nasopharyngeal polpys tend to occur in younger cats usually under a year of age.

How are nasopharyngeal polyps diagnosed?

It may be possible to see the polyp at the back of the throat when examining the mouth but it is usually necessary to anaesthetise the cat to obtain a good view behind the soft palpate which is a sensitive area to investigate.  Sometimes the use of a specialist endoscope may enable direct visualisation of the polyp.  If your veterinarian is uncertain whether a mass is a polyp, a biopsy for microscopic pathological examination may be recommended.  In some cats with nasopharyngeal polyps, part of the polyp may penetrate the ear drum and grow out through the ear canal.  This may be visible on close inspection of the ear.

"If your veterinarian is uncertain whether a mass is a polyp, a biopsy for microscopic pathological examination may be recommended."

How are nasopharyngeal polyps treated?

It is usually very straightforward to remove the bulk of a nasopharyngeal polyp by simply pulling it away from the back of the throat which will immediately alleviate the clinical signs and results in a cure in around 75% of cases.  Sometimes the stalk of the polyp is left behind and the polyp recurs after removal by simple traction.  If there is involvement of the auditory canal it may be necessary to perform a bulla osteotomy which is an operation opening the middle ear cavity, allowing the stalk of the polyp to be removed.  This is the most effective treatment for preventing recurrence but is a major surgical procedure and mild surgical complications are common. 

What is the outlook for cats with nasopharyngeal polyps?

Although there is a risk of recurrence, nasopharyngeal polyps can be resolved effectively in most cats and long-term outlook is very good.  Although side effects are quite common with surgery, most are transient and cats are often cured of this problem.