Outer Ear Inflammation or Infection (Otitis Externa) in Dogs

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Last updated on
6 min read

Key takeaways

Otitis externa is inflammation of the external ear canal and is often referred to as an ear infection. Ear infections and otitis externa are common in dogs.

  • Affected dogs are often observed shaking their head or scratching their ears
  • There may be visible debris in the ear, and a foul odo
  • Otitis externa is a complicated condition caused by a range of many primary, secondary, predisposing and perpetuating factors
  • Examples of associated conditions include allergies, bacterial or yeast infections, and ear conformation
  • Diagnosis involves cytology and/or culture, and treatment often involves cleaning the ears, administration of antibiotics, and managing the underlying cause
  • Recurrence and treatment failure are very common, mostly due to failure to identify all underlying causes
  • Prevention involves managing the underlying cause and prognosis is usually good
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A closer look: Outer Ear Inflammation or Infection (Otitis Externa) in Dogs

Outer ear inflammation and infection is associated with many different underlying conditions and predisposing factors in dogs. The rates of recurrence are high especially if underlying conditions are not well managed. Ongoing monitoring and veterinary guidance are necessary to control recurrent infections.

Symptoms of otitis externa vary based on the underlying cause. Examples include:

  • Black, coffee-ground like material often indicates ear mite infection
  • Yeast infections often have a distinct, yeasty odor
  • Thickening of the ear canal is often seen with chronic inflammation

When ear irritation is persistent, non-urgent veterinary care is the best course to prevent more serious infection from developing.

While not an emergency, ear inflammation is itchy and uncomfortable for affected dogs. Otitis externa is often frustrating for owners as it can require ongoing management, and recurrence is common without a proper treatment plan or preventive measures. Overall, it usually has a favorable prognosis with proper treatment and management of underlying causes.

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Risk factors

Otitis externa is a very common condition affecting any breed of dog. Some breeds of dogs are more prone to suffering from otitis externa due to anatomical features of the ear. Dogs with long, pendulous, and heavy ears, or those with a large amount of hair growing in the ear canal are more prone to developing otitis externa.

Other risk factors include dogs that regularly swim or otherwise get their ears wet, or dogs that have underlying allergic skin disease such as atopy or food allergies.

There are several predisposing factors that can increase the risk of a dog developing otitis externa. These include anatomic changes such as hyperplasia, tumors or polyps in the ear, narrowing of the ear canal, or large amounts of hair growth and environmental factors such as elevated ambient temperature and humidity.

There are also perpetuating factors that can prevent resolution of otitis externa, even if the primary factor has been resolved. These factors are a result of chronic inflammation of the ear, and include physical changes to the ear canal itself, as well as the eardrum.

Possible causes

Otitis externa is primarily caused by an underlying condition in the ear.

Failure to properly identify and treat any of the above primary causes are often the cause for treatment failure and recurrence of outer ear inflammation and infection.

Secondarily, otitis externa can be caused by various bacterial, yeast or fungal infections. Aggressive ear cleaning has also been linked to this condition.

Main symptoms

Testing and diagnosis

Diagnosis of otitis externa begins with a physical examination. Examination of the ear canal with an otoscope helps identify changes that warrant further investigation. Diagnostics to determine the cause of otitis externa include

  • Microscopic examination of cells swabbed from the ear canal
  • Bacterial or fungal culture
  • Diagnostic imaging such as MRI if cancer or polyps are suspected.

Steps to Recovery

Treatment of otitis externa involves resolving the underlying cause of the infection. This may involve management of allergies, treatment of bacterial, yeast, or fungal infections with antibiotics or antifungals, or removal of foreign bodies, tumors/masses, or polyps.

Otitis externa generally does not resolve on its own, and without treatment the condition may progress further. A possible complication of otitis externa is progression to an inner or middle ear infection.

Prognosis depends on the underlying condition and is good in most cases. Most dogs make a full recovery with proper treatment. Otitis externa caused by neoplasia has a more guarded prognosis.

Dogs diagnosed with otitis externa require close monitoring, as recurrence is very common. Frequent rechecks and cytologic examination are required to determine how treatment is progressing and if any changes are needed. Recurrence and treatment failure are often caused by poor cleaning technique, or stopping treatment too early. In the absence of a culture to check for infectious causes, recurrence may occur if the incorrect medication is chosen to treat.

Failure to address all underlying causes of otitis externa is a major factor in treatment failure and recurrence.


Management of underlying conditions is key to prevention of otitis externa. This involves treatment and management of endocrine disorders, allergies, infections, and autoimmune disease.

Other ways to prevent otitis externa is ensuring dogs’ ears are properly dried after swimming, learning how to properly clean a dog’s ears, and cleaning ears when they appear dirtier than normal.

Otitis externa is not contagious to other dogs or people.

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

Otitis externa is very common in dogs.

Typical Treatment

  • Ear cleaning
  • Antibiotics
  • Antifungals
  • Steroids
  • Treatment of underlying causes

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