Ear polyps in cats are a fairly uncommon occurrence but can cause severe damage to the tympanic membrane (eardrum) if not properly diagnosed or treated. Ear polyps can occur in cats of all ages but are usually seen in cats between the ages of 1 and 4. They affect all breeds and both sexes equally. The exact cause of ear polyps is not known, however, some theories suggest that they result from a reaction to inflammation, possibly caused by bacteria, fungi, or calicivirus. Another possibility is that they originate from some remnants of brachial arches that are present in early fetal development.
What are the symptoms?
The symptoms of polyps include those of an outer or middle ear infection. The cat may shake or scratch at its head, have pain on palpation of the ear, or it may have a thick or bloody discharge from the ear canal. Cats may also present with a head tilt and inability to walk in a straight line, or they may also have a droopy eyelid or the third eyelid may partially cover the eye. The symptoms usually start slowly and become chronic with limited response to routine treatment.
Polyps can also occur in the nasal passages and throat. Cats with polyps in these locations may have difficulty breathing or swallowing.
How are ear polyps diagnosed?
Diagnosis is usually based on a thorough exam of the ear canal with an otoscope. Some cats may need to be sedated to properly examine the entire ear canal. The polyps are usually located in the horizontal part of the ear canal, which is difficult to visualize without an otoscope. Once the polyp is identified, it can be biopsied to rule out the possibility of it being a squamous cell tumor. X-rays of the head can also identify the presence of an ear polyp.
How are they treated?
Treatment usually consists of surgical removal. Because the polyps are usually attached by only a thin, long stalk they can usually be pulled up and the stalk can be cut. The problem with simple removal is that if the base (source) of the polyp is not removed, then 50% to 75% of the polyps will reoccur in 1 to 8 months. Therefore, a more complicated, but thorough, surgical procedure called a ventral bulla osteotomy is recommended. This surgery removes the lower part of the bone that surrounds the inner ear. These surgeries are delicate and often best performed by a surgical expert. If the ventral bulla osteotomy is performed, the reoccurrence rate is extremely low. Depending on the original cause or the presence of infection, an antibiotic may be given for a several weeks after the surgical procedure is performed.
Post surgical care and prognosis
After the surgery, the cat should recover fully in several weeks. Some cats may have some mild nerve damage that causes the eyelid to droop or even some incoordination and difficulty walking. In the majority of these cases, these symptoms go away in several weeks, although, in some rare cases, they may be permanent. As we mentioned earlier, if the ventral bulla osteotomy is performed, reoccurrence is very unlikely, and is therefore, the current recommended treatment.
Ear polyps in cats primarily occur in young healthy individuals. While ear polyps are uncommon, they should always be considered in cats that have reoccurring or severe ear infections. Because a veterinarian can only diagnose them with a thorough otoscopic exam, we recommend that a veterinarian examine all cats with ear infections before any treatment is started. Treatment is usually successful and surgical removal of the polyp can prevent serious damage to the eardrum.
Rosychuk, R.A.; Luttgen, P. Diseases of the Ear. In Feldman, E.; Ettinger, S. (eds.) Textbook of Veterinary Internal Medicine. W.B. Saunders Co. Philadelphia, PA; 2000; 986-1002.
Swalec Tobias, K. Management of ear and nasopharyngeal polyps in cats. Veterinary Forum. May 2000.