Outer Ear Inflammation or Infection (Otitis Externa) in Cats

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Key takeaways

Otitis externa is inflammation of the external part of the ear canal. In cats, otitis externa is most commonly caused by ear infections and the terms are often used synonymously.  

  • Primary otitis can be caused by ear mites, allergies, foreign bodies, and endocrine or autoimmune disorders
  • Otitis externa can also be caused by secondary  bacterial or yeast infections
  • Outer ear inflammation often presents with pain and discomfort in the affected area, excessive rubbing and pawing of the ear, redness, foul odor, and head shaking
  • Diagnostics include complete physical examination including an otoscopic examination under sedation or anesthesia
  • Biopsy, cytology, allergy testing, and/or diagnostic imaging might also be required
  • Treatment depends on the underlying condition and can consist of topical medications, ear cleaning, parasite control, allergy medications, and surgery
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A closer look: Outer Ear Inflammation or Infection (Otitis Externa) in Cats

Otitis externa refers to outer ear inflammation, but it is often used synonymously with ear infections in cats. Any illness or infection associated with the ears has the potential to cause inflammation and discomfort. Non-urgent veterinary care is suggested at the first sign of persisting ear discomfort. Early detection and treatment create the best circumstances to prevent a more serious infection from taking hold.

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Risk factors

Otitis externa is more common in dogs than in cats. The prognosis is good overall, with the condition clearing after 2 to 4 weeks. The risk of recurrence is high and complications, such as hearing loss or otitis media and interna, are possible.

Symptoms may vary in severity according to the underlying cause of otitis externa. In some cases, the inflammation can spread to the pinna, the outermost part of the ear, which can present with ulcerations, swelling, red skin, and erosion.

Scarring and changes in the shape of the ear canal increase the risk of recurrence. Complications might include hearing loss and otitis media or interna.

Possible causes

There are many possible causes for ear inflammation or infection in cats. Identifying the underlying condition is fundamental for effective treatment.

Rarely, primary causes may also include endocrine or autoimmune disorders, such as

  • Hyperadrenocorticism
  • Pemphigus complex
  • Llupus erythematosus

Secondary causes include:

  • Bacterial infections
  • Yeast infections
  • Aggressive ear cleaning

Main symptoms

Testing and diagnosis

The diagnostic process focuses mainly on detecting the primary source of otitis externa.

Diagnostic tools include:

  • A complete physical examination
  • An otoscopic examination (cats might require sedation for this test, especially if the ear canal is obstructed, painful, or the patient is uncooperative)
  • Cytology
  • Diagnostic imaging
  • Allergy tests
  • Biopsy in cases of tumors or polyps

Steps to Recovery

For treatment to be effective, targeting the underlying condition is fundamental. Specific therapies such as antiparasitics or allergy medications might be prescribed.

Topical medications are usually needed as well. Most topical ear medications include a combination of antifungals, steroids, and antibiotics and can be applied directly on the area.

Ear cleaning is necessary to allow the medications to work properly. The veterinarian might need to gently clean and dry the ears before starting the treatment.

Depending on the underlying condition, surgery might be needed in severe cases.

Cats usually need up to 2 to 4 weeks to fully recover from otitis externa. Recovery in cases of mites infestation might take longer. The risk of recurrence is high, especially in cases of fungal or parasitic infections.

Cats are not always agreeable patients, so at-home administration of medication has variable success. Frequent monitoring and ear cleaning are often needed.


Otitis externa is not contagious in and of itself but some associated infections might be. For example, mites are particularly contagious and treatment of all animals in the household may be necessary to control further spread or re-infection.

Preventive measures include management of underlying conditions such as allergies and external parasite control. Staying up to date with regular vet appointments and vaccinates helps ensure overall health and catch deve;oping conditions early.

Is Outer Ear Inflammation or Infection (Otitis Externa) in Cats common?

Otitis externa is common in cats.

Typical Treatment

  • Specific treatment for underlying conditions
  • Topical medications
  • Ear cleaning
  • Surgery


Karen A. Moriello , DVM, DACVD - Writing for Merck Veterinary Manual
Michelle Woodward , DVM, DACVD - Writing for Merck Veterinary Manual
Ryan Llera, BSc, DVM; Ernest Ward, DVM - Writing for VCA Animal Hospitals
Wendy Brooks, DVM, DABVP - Writing for Veterinary Partner

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