Polyps (pronounced pol-ips) are basically benign (non-cancerous) overgrowths of tissue. They are composed of a rounded blob of tissue attached by a thin stalk and are particularly common in cats, especially young cats.
What causes polyps?
The million-dollar question! Well, whilst we suspect that upper respiratory tract infections with viruses may be behind the development of polyps, we still aren’t completely certain if there are additional underlying causes. In cats the polyps are normally made up of fibrous and inflammatory cells, which we believe is related to the inflammation caused by a respiratory virus, although the signs caused by the polyp will often not appear until months after the cat was infected.
Where are they?
There are three key places we often find polyps in cats.
- In the ear canal
- Within the middle ear (so beyond the ear drum)
- In the back of the throat – here they often start in the middle ear and grow down, exiting through the Eustacian tube and into the back of the throat!
There are also other types of polyps that can occur in the body. For example, colorectal polyps are found in the large intestine and inside the rectum. These can sometimes be felt on palpation or seen if the cat has a coloscopy procedure, where a camera is used to check inside the rectum and the colon.
What signs do polyps cause?
So, again, this depends on where they are. Polyps that are in the external ear canal might cause signs of an ear infection such as scratching at the ear, abnormal discharge within the ear, or shaking the head. Those with middle ear polyps might have signs similar to a middle ear infection. This can include bothering with the ear but more frequently are associated with abnormal balance, changes in pupil sizes, tilting the head, and nystagmus or flickering of the eyes.
Where a polyp is nasopharyngeal, so not in the ear but at the back of the throat, above the soft palate, the cat normally shows more respiratory-type signs. These include sneezing, nasal discharge, sometimes reverse sneezing (a startling honking sound that’s basically a reflex caused by the cat trying to clear the throat). Occasionally, we see some other signs like noisy breathing and pawing at the mouth.
How can the vet diagnose polyps?
In a cat that has a history of recurrent respiratory or ear infections, we start to suspect that there may be an underlying cause, including a polyp. Sometimes using an otoscope to check down the ear canal will show a polyp or changes in the eardrum that suggest there may be one present in the middle ear. If the cat is having respiratory tract infections or nasal discharge, we will often recommend examination under sedation to have a look around the mouth, nose and throat.
For nasopharyngeal polyps, we can often see the soft palate bulging down into the back of the throat. Lifting the palate a little unveils the polyp sat there. Sometimes, however, it might not be so straightforward. We can’t see everything by direct examination, and we may recommend further tests like radiographs or a CT scan. This could then identify a possible polyp.
How are polyps treated?
Generally, polyps are fast and uncomplicated to treat. Easy-to-reach nasopharyngeal and ear polyps can be removed using gentle, steady traction on the mass of tissue, with the cat under general anaesthetic. It’s normally a very short procedure and the cat recovers quickly. There is often a rapid improvement in the signs it showed before the surgery.
What is the prognosis for cats with polyps?
Cats that have been diagnosed with polyps often enjoy a rapid resolution of their signs after appropriate removal. In some cases, the entire stalk of tissue cannot be completely removed and some gets left behind. This can mean that the polyp regrows and causes the signs to recur in the future, requiring another procedure. It is more common for those that originate in the middle ear.
In such cases, or where a polyp is causing a middle ear infection, a further operation called a ventral bulla osteotomy (VBO) can be done to help prevent a recurrence. However, this is a much more invasive procedure not without its own risks and it often requires a specialist. Both VBO and removal by traction can cause some negative side effects such as nerve damage, but, in most cases, this resolves with time.
Generally speaking, cats go on to live normal lives when the polyp has been addressed.
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