Affected Animals:
Any animal can suffer from otitis.

Overview: From ear mites to cancer, a diverse array of medical conditions can cause cats to develop ear infections.  Allergies, the formation of a polyp or tissue growth in the middle ear, trauma to the ear from scratching, bacteria, yeast, and many diseases all can lead to otitis, or inflammation of the ear canal.

Cats frequently will shake their heads and scratch their ears when they have otitis because of discomfort and irritation.  Generally, medications are successful at treating most cases of otitis, but if allergies or other complicating underlying conditions are causing the inflammation, additional measures may need to be taken to eliminate the problem.

The veterinarian will need to examine the outside of the ears, as well as the ear canal and tympanic membrane or eardrum to see if there are any abnormalities.  Sometimes sedation or general anesthesia will be needed to allow the ears to be examined and cleaned thoroughly and to perform diagnostic tests.

Clinical Signs:
Most cats that have problems with their ears will shake their heads, scratch the ears, and rub their heads on surfaces.  The ears may have an odor to them.  Sometimes the ear can develop an aural hematoma, or a swelling on the earflap that is soft and warm to the touch, which results from repeated scratching and shaking.

Symptoms:
See clinical signs.

Description: Clinically known as otitis, an ear infection is a broad term describing inflammation of the ear, which can have many causes.  Otitis can involve the outer, middle, or inner part of the ear.  Generally, otitis that involves the inner part of the ear is more severe and can result in permanent hearing loss and difficulty maintaining balance and coordination.  Some examples of conditions that can cause otitis include ear mites, the formation of a polyp or tissue growth in the middle ear, trauma from scratching, allergies, bacteria, yeast called Malassezia pachydermatis, and cancer.

Any inflammation or infection can cause cats to experience discomfort and irritation.  Medications are available that treat otitis; they vary according to the underlying condition causing the infection.

Diagnosis: After obtaining a thorough medical history from the owner about the cat's symptoms, environment, and history of illness, the veterinarian will perform a complete physical exam, using an otoscope to examine the ears and their canals.  Some cats may need to be sedated so that their ears can be examined properly.

Other tests that may be performed include cytology, in which the veterinarian takes a swab from the ears and examines this material under the microscope for abnormalities such as ear mites, yeast, and bacteria.  This test provides the veterinarian with a tremendous amount of information about the condition of the cat's ears.  If the cytology reveals evidence of a severe bacterial infection, a culture may be necessary to identify the type of bacteria and the appropriate antibiotics that can be prescribed.

Prognosis:
With the proper diagnosis, cleaning and treatment, most cases of ear infections will resolve in seven to 14 days, depending on the underlying cause.  Some cats that have allergies and develop otitis may experience recurrences; it is important that the sources of the allergy be determined so that owners can prevent the cat's exposure to them.  The veterinarian will be able to determine the cause of the otitis and make appropriate recommendations.

Transmission or Cause:
There are several causes of otitis in cats.  One of the more common causes is ear mites called Otodectes cynotis, which are transmitted from one animal to another through close contact.  Dogs and cats can transmit ear mites to one another.  The mites that live in the ears cause significant irritation that leads to the production of a dark, brown, waxy material called cerumen.
 
Other causes of otitis include allergies to topical medications, to certain foods, and to particles or allergens in the air such as tree pollen and house dust.  Cats also can develop otitis when the normal yeast in the ear called Malassezia pachydermatis overgrows and causes a yeast infection.  Bacterial overgrowth in the ears also can cause infections.  Many more causes of otitis exist, so it is important that a veterinarian examine the cat thoroughly.

Treatment: Treatment will depend on the diagnosis. However, before determining which medication should be used to treat the infection, the veterinarian will assess the eardrum to ensure that it is intact, since certain medications should not be used if the eardrum is ruptured or destroyed.

After diagnosis of the otitis, the veterinarian will perform a thorough cleaning of the ears and evaluate the eardrum to see if it is intact.  Some cats will need sedation or general anesthesia before the examination and cleaning can be done, since most cats will have great sensitivity in their ears and will not allow their ears to be handled or examined.

Owners who clean the cat's ears at home should never use cotton tipped applicators because these can do more harm than good.  The use of warm, sterile saline can be used instead to gently flush and clean out the ears.  The veterinarian will be able to describe a proper cleaning regime that is best for the individual cat's situation.

Prevention:
With the proper diagnosis, cleaning and treatment, most cases of ear infections will resolve in seven to 14 days, depending on the underlying cause.  Some cats that have allergies and develop otitis may experience recurrences; it is important that the sources of the allergy be determined so that owners can prevent the cat's exposure to them.  The veterinarian will be able to determine the cause of the otitis and make appropriate recommendations.