Ear infections can be miserable for both dogs and humans. Chronic ear infections in dogs are particularly nasty and can take a lot of time and effort to treat effectively.

You might have heard your veterinarian refer to your dog’s chronic ear infection as “Chronic otitis,” – but what does this mean? What causes these long-standing, difficult-to-treat infections? Let’s have a look.  

Key Takeaways:

  • Chronic otitis in dogs refers to a long-standing ear infection characterized by ear inflammation lasting a month or more.
  • Treatment includes antibiotics (ear drops), addressing underlying causes, and additional measures like cleaning or surgery.
  • Prompt veterinary care is crucial to prevent discomfort and complications.

What Is Chronic Otitis in Dogs?

Chronic otitis in dogs refers to a long-standing ear infection characterized by inflammation of the ear. It is a persistent condition that lasts for a month or more. The term "otitis" denotes inflammation of the ear, and "chronic" indicates the duration of the infection.

Signs & Symptoms of Chronic Otitis in Dogs

Dogs with a chronic ear infection may have many different symptoms, including:

  • Redness around the outside of the ear
  • Swelling around the base of the ear
  • Itchiness around the ear, which may cause them to scratch the ear or rub it along the floor
  • Pain when the ear is touched
  • Thick, sticky fluid coming from the ear.

If left untreated, chronic otitis is one of the most common causes of a middle or inner ear infection in dogs. The symptoms of an inner ear infection include:

  • Tilting the head to one side
  • Loss of balance
  • Falling to one side
  • Eyes flickering (“nystagmus”)

What Causes Chronic Otitis in Dogs? 

Chronic otitis is usually caused by a bacterial infection in the ear. These infections are not usually contagious (they cannot pass between dogs) but instead are caused by an overgrowth of the bacteria and yeasts that are naturally found within the ear. This overgrowth happens as a result of some problem within the ear. 

Several different kinds of problems can cause chronic ear infections in dogs, including:

  • Seasonal allergies
  • Water in the ear, usually from bathing or regular swimming
  • A hormone problem, such as an underactive thyroid
  • Ear mites
  • A foreign body in the ear canal, such as a grass awn.

It is important that your veterinarian determines the exact cause of your dog’s ear infection, as the treatment for each of these conditions may be different. 

Diagnosis for Chronic Otitis in Dogs

There are several different tests that your veterinarian may recommend to work out what is causing your dog’s ear infections. These include:

  • Taking some material from the ear and examining it under a microscope to look for signs of ear mites and to try and see which types of bacteria are present.  
  • Take a swab from the ear to see exactly which bacteria or yeasts are causing the problem and ensure your dog is on the correct antibiotics.
  • Blood tests, including a thyroid panel, to check for underlying illnesses that might weaken your dog’s immune system. 
  • Examining the ear under sedation or anesthesia to see if there are any signs of a foreign body within the ear and to allow them to flush the discharge out of the ear. 
  • Allergy testing may include a special blood test or intradermal tests

Your vet will consider your dog’s age, breed, and any other symptoms they may be showing and recommend the tests they think are appropriate. 

If your vet thinks your dog may have an inner ear infection, they may recommend referral to a specialist, as advanced imaging (MRI or CT scan) is needed to diagnose the issues accurately.

Alternatively, X-Rays can sometimes be used if advanced imaging is not available. 

How to Treat Chronic Otitis in Dogs  

Treating chronic otitis in dogs involves addressing both the infection and the underlying cause. To treat the infection, appropriate antibiotics are prescribed, often in the form of ear drops. Ear drops offer targeted delivery and a higher concentration of antibiotics to combat the infection effectively. However, if the discharge is present or a burst eardrum, alternative treatment options may be considered, including ear cleaning or surgical intervention.

In addition to treating the infection, addressing the underlying cause of the ear infection is essential. Treatment plans vary depending on the specific cause, which may involve removing foreign bodies, managing allergies, or implementing long-term solutions for underlying conditions.

Related reading: Home Remedies for Ear Infections in Dogs


Ear infections are itchy and painful for your dog and can be difficult and expensive to treat. If you suspect your dog has an ear infection, do not delay – book a visit with a veterinarian today to get them checked out. 

Related Reading: Ear Infections in Dogs: Symptoms, Causes, & Treatment