Otitis externa in dogs is inflammation of the external ear canal, commonly associated with bacterial or yeast infections. It can cause itching, head shaking, unpleasant smells, discharge and significant discomfort. Although most uncomplicated cases respond well to veterinary treatment, recurring or untreated inflammation can lead to more serious ear problems.

If your dog has started scratching its ears, shaking its head or pulling away when you touch its head, an ear problem may be responsible. Understanding the possible causes is important because simply treating an infection without addressing an underlying allergy or other condition can allow symptoms to return.

This guide explains the signs of otitis externa, why some breeds are more susceptible, how vets diagnose and treat it, and what you can do to help protect your dog's ear health.

What Is Otitis Externa in Dogs?

Otitis externa is inflammation affecting the external ear canal, the passage that carries sound towards the eardrum.

The ear canal contains skin, glands and a normal population of microorganisms. When the skin becomes inflamed, changes in moisture, wax production and the local environment can allow bacteria or yeast to multiply excessively.

Although owners often call the condition an ear infection, not every case begins with an infection. Allergies, parasites and foreign material can cause inflammation before secondary infection develops.

Otitis externa can affect one or both ears and may develop suddenly or become a long-term recurring problem.

It differs from otitis media, which affects the middle ear, and otitis interna, which affects the inner ear.

What Are the Symptoms of Otitis Externa in Dogs?

Common signs of otitis externa include frequent head shaking, scratching at the ears, redness, discharge, an unpleasant smell and pain when the ears are touched.

Symptoms vary according to the underlying cause and severity.

Early Signs of an Ear Infection

Look for the following changes:

• Repeated head shaking or ear scratching.
• Rubbing the head against furniture or carpets.
• Redness inside the ear.
• Increased wax or unusual discharge.
• An unpleasant smell coming from the ear.
• Sensitivity when the ear or surrounding area is touched.
• Holding one ear differently or tilting the head.

Some dogs become quieter, irritable or reluctant to have their head handled because the ear canal is painful.

What Does a Severe Ear Infection Look Like?

More advanced inflammation may cause marked swelling, thick discharge, severe pain or narrowing of the ear canal.

Sudden loss of balance, circling, abnormal eye movements or a persistent head tilt may suggest involvement of the middle or inner ear and requires urgent veterinary assessment.

What Causes Otitis Externa in Dogs?

Otitis externa usually develops through a combination of underlying causes and contributing factors.

Allergies and Skin Disease

Allergic skin disease is one of the most important causes of recurring ear inflammation.

Dogs with environmental allergies or adverse food reactions may develop inflammation in the ears alongside itchy paws, skin redness or repeated licking and scratching.

Some dogs develop ear problems as one of their main allergy symptoms, even when the rest of their skin appears relatively normal.

Yeast Infections

Malassezia yeast normally occurs on canine skin in small amounts. When the ear environment becomes inflamed or altered, yeast can multiply and contribute to irritation, waxy discharge and odour.

Yeast overgrowth is often secondary to an underlying problem rather than the original cause.

Bacterial Infections

Bacteria can also multiply in inflamed ear canals. Common organisms include Staphylococcus species and, in some persistent infections, Pseudomonas species.

Different organisms require different treatment approaches, which is why examining ear samples under a microscope can be useful.

Ear Mites and Foreign Bodies

Ear mites can cause itching and inflammation, particularly in young dogs or those exposed to affected animals.

Grass seeds and other foreign material may become lodged in the ear canal, causing sudden discomfort and repeated head shaking, sometimes affecting only one ear.

Moisture and Ear Anatomy

Swimming, bathing and naturally narrow ear canals can create conditions that favour inflammation.

Dogs with heavy hanging ears, excessive hair around the canal or narrowed ear openings may be more susceptible, especially when other causes are present.

Excessive cleaning can also irritate the ear canal and worsen existing inflammation.

Is Otitis Externa Hereditary in Dogs?

Otitis externa is not generally inherited as one single disease caused by a particular gene.

However, inherited physical characteristics and predispositions to allergic skin disease can increase a dog's risk.

Examples include the shape of the ear canal, heavy hanging ears and breed-related tendencies towards skin allergies.

Some dogs inherit anatomical features that make ear ventilation or natural wax clearance less effective.

Genetics therefore influence susceptibility, but environmental factors, underlying disease and everyday ear care also contribute.

There is no universal DNA test that predicts whether an individual dog will develop otitis externa.

Which Dog Breeds Are Most Prone to Ear Infections?

Any dog can develop otitis externa, but research shows that some breeds are affected more frequently.

Basset Hounds

Basset Hounds have heavy hanging ears and are among the breeds with a particularly high recorded risk of otitis externa.

Chinese Shar Peis

Chinese Shar Peis may have naturally narrow ear canals, which can make examination, cleaning and treatment more challenging.

Labradoodles and Cockapoos

Labradoodles and Cockapoos can be susceptible because of their ear anatomy, coat characteristics and potential predisposition to allergic skin disease.

Our guide to common health issues in Labradoodles explains how allergies and ear structure can contribute to repeated inflammation.

Similarly, our article on common health problems in Cockapoos discusses recurring ear infections and itchy skin.

Other Susceptible Breeds

Beagles, Golden Retrievers, French Bulldogs, Poodles and several Spaniel breeds may also have increased susceptibility.

Research from the RVC found that approximately 7.3 per cent of dogs in its UK study experienced otitis externa during the study year.

Breed predisposition increases risk but does not mean that every dog of that breed will develop ear disease.

How Do Vets Diagnose Otitis Externa?

Diagnosis begins with a physical examination and questions about your dog's symptoms, previous ear problems, swimming habits, allergies and current medication.

Ear Examination

Your vet will examine the outer ear and, where possible, use an otoscope to inspect the ear canal and eardrum.

They may look for swelling, discharge, foreign bodies, abnormal growths and evidence of damage to the eardrum.

Ear Cytology

Ear cytology involves collecting a small sample of discharge and examining it under a microscope.

This helps identify yeast, bacteria and inflammatory cells, allowing treatment to be selected more accurately.

Additional Investigations

Persistent or severe infections may require bacterial culture and susceptibility testing, particularly when treatment has not worked as expected.

Dogs with recurring problems may also need investigation for allergies, hormonal disease or middle-ear involvement.

Very painful ears sometimes require sedation or anaesthesia for a thorough examination and safe cleaning.

How Is Otitis Externa Treated in Dogs?

Treatment aims to relieve pain, reduce inflammation, control infection where present and address the underlying cause.

The most appropriate treatment depends on what your vet finds during examination and testing.

Prescription Ear Medication

Many dogs receive medicated ear drops containing an antibacterial, antifungal or anti-inflammatory ingredient, sometimes in combination.

Your vet will select medication based on the organisms present, inflammation and whether the eardrum is intact.

Some ear preparations can be unsafe when the eardrum is damaged, so using leftover drops without examination is not recommended.

Professional Ear Cleaning

Removing excessive wax and discharge can help medication reach the inflamed ear canal.

Some dogs require professional flushing under sedation or anaesthesia, particularly when the ear is severely painful or obstructed.

Treating Underlying Allergies

If allergic skin disease is contributing to recurring infections, controlling the allergy is an essential part of long-term treatment.

This may involve veterinary-prescribed medication, environmental management or a carefully supervised dietary investigation.

Repeatedly treating yeast or bacteria without addressing the underlying inflammation can result in recurring episodes.

How Long Does Treatment Take?

Many uncomplicated cases improve within days of starting appropriate treatment, but complete resolution may take several weeks.

Chronic or severe infections can take considerably longer and may require repeat examinations.

Do not stop prescribed treatment early simply because the smell or scratching has improved.

Can You Treat a Dog's Ear Infection at Home?

Home care can support veterinary treatment, but it should not replace diagnosis when an ear is painful, red or producing discharge.

Only use ear cleaners or medication recommended for your dog's condition.

Avoid vinegar mixtures, hydrogen peroxide, essential oils and human ear medication. These can irritate inflamed tissues and may be harmful if the eardrum is damaged.

Never insert cotton buds deep into the ear canal, as they can push material further inside or cause injury.

If your vet recommends cleaning, ask for a demonstration and follow the advised frequency. More cleaning is not always better.

What Happens if Otitis Externa Is Left Untreated?

Untreated inflammation can become chronic and progressively damage the ear canal.

Repeated episodes may lead to thickened skin, increased gland activity, narrowing of the canal and, in advanced cases, mineralisation of the surrounding tissues.

Infection can sometimes extend into the middle ear, causing additional pain and potentially affecting hearing or balance.

Severe chronic disease may become difficult to manage with medication alone. In selected cases, specialist surgery may be necessary.

However, most uncomplicated cases have a good outlook when the cause is identified and appropriate treatment begins early.

Otitis Externa in Dogs: Symptoms, Causes and Possible Outcomes

How Can You Prevent Recurring Ear Infections in Dogs?

Not every episode is preventable, particularly when a dog has inherited ear anatomy or chronic allergic disease.

However, sensible ear care and management of underlying conditions can reduce the risk of recurrence.

Useful habits include:

• Check the ears regularly for redness, discharge or unusual smells.
• Follow your vet's advice about cleaning frequency.
• Use only appropriate veterinary-recommended ear cleaners.
• Monitor dogs with allergies for recurring itching or ear irritation.
• Keep up with recommended follow-up appointments.
• Seek advice if symptoms return rather than repeatedly using old medication.

Dogs that swim frequently may benefit from an individual ear-care routine, but avoid unnecessary cleaning or aggressive removal of hair from the ear canal.

For owners of allergy-prone breeds, our guide to common health problems in French Bulldogs

When Should You Take Your Dog to the Vet for an Ear Infection?

Arrange veterinary advice promptly if your dog develops persistent head shaking, scratching, discharge, redness, an unusual smell or pain around the ears.

Seek urgent care for severe pain, marked swelling, loss of balance, abnormal eye movements or a persistent head tilt.

These symptoms may indicate a foreign body, significant inflammation or disease extending beyond the external ear canal.

Our broader guide to common medical conditions in dogs and their warning signs

Frequently Asked Questions About Otitis Externa in Dogs

Can a Dog's Ear Infection Go Away on Its Own?

Mild irritation may occasionally improve, but a painful or infected ear should not be left untreated. Without identifying the cause, inflammation can persist or recur.

Is Otitis Externa Painful for Dogs?

Yes. Otitis externa can be very uncomfortable or painful, particularly when the canal becomes swollen or ulcerated. Dogs may resist having their ears touched.

Can Dogs Get Ear Infections From Swimming?

Swimming can contribute to ear problems in susceptible dogs because moisture changes the ear canal environment. However, allergies and other underlying causes often play a larger role.

Are Dog Ear Infections Contagious?

Most bacterial and yeast ear infections are not readily contagious between dogs. Ear mites, however, can spread between animals and require appropriate treatment.

Why Does My Dog Keep Getting Ear Infections?

Recurring infections often indicate an underlying issue such as allergic skin disease, ear anatomy, persistent moisture or another medical condition. Repeated episodes warrant investigation rather than treatment with the same drops indefinitely.

Can an Ear Infection Cause Deafness in Dogs?

Severe or chronic ear disease can impair hearing, particularly when the ear canal becomes obstructed or the middle ear is affected. Early treatment reduces the risk of lasting complications.

Final Thoughts

Otitis externa in dogs is common, often painful and usually treatable when the underlying cause is identified.

Recognising early signs, following veterinary treatment instructions and investigating repeated episodes can help protect your dog's comfort and hearing.

If your dog repeatedly shakes its head, scratches its ears or develops discharge, arrange a veterinary examination rather than relying on home remedies.

This article provides general educational information and does not replace individual veterinary diagnosis, treatment or emergency care.