Ear Canker otitis in Cats

By Sophie Kininmonth · 15 Jan 2026 (updated 21 Jul 2026) ·7 min read

"Ear canker" is the informal name people still reach for when a cat's ears suddenly smell wrong, look messy, or the cat won't stop shaking its head and scratching at them. Vets call the same problem otitis, meaning inflammation or infection of the ear. It can be simple irritation of the outer canal, or it can be the first sign of mites, yeast, bacteria, or a deeper infection that affects balance and hearing. The most useful thing to understand up front is that "ear canker" is a symptom, not a diagnosis. The cause needs to be worked out before anything goes into the ear.^{1, 2, 3, 4}

What "ear canker" means in cats

In cats, "ear canker" most often means otitis externa: inflammation of the outer ear canal. The canal becomes warm, swollen and reactive, and it produces more wax and discharge. That debris traps moisture and irritates the skin further, which is exactly the environment a secondary infection settles into.^{2, 5}

If the problem spreads past the eardrum, it becomes otitis media (middle ear) or otitis interna (inner ear). That is the stage where you may see balance problems, a head tilt, or facial nerve signs, and where the risk of lasting damage rises.^{1, 6}

Common causes, and why the cause matters

Otitis is rarely just one thing. Usually there is an underlying trigger plus a secondary overgrowth of bacteria or yeast on top of it. Discharge that looks identical can come from different causes, and the wrong drops can make things worse, especially if the eardrum is already damaged.^{4, 5}

Ear mites (Otodectes cynotis)

Ear mites are a frequent cause of otitis externa in cats, especially kittens and cats with outdoor exposure or contact with other cats. They tend to leave a dark, crumbly or gooey wax with a strong smell, and they can drive intense scratching and head shaking.^{2, 3}

Yeast and bacteria

Yeast, including Malassezia, and bacteria can overgrow when the ear canal's normal climate changes: more wax, more moisture, more inflammation. These infections can be primary, or secondary to mites, allergy, polyps, or other irritation.^{2, 5}

Allergy, skin disease, and other underlying problems

Some cats develop recurring ear inflammation as part of broader skin disease, including allergy. Others have physical contributors such as inflammatory polyps, which in cats are more commonly linked with middle ear disease, or foreign material lodged in the canal.^{1, 7}

Signs you might notice at home

Otitis in cats tends to announce itself through small, repetitive behaviours and a few clear sensory clues.

Head shaking, ear flicking, or rubbing the ear on furniture⁵
Scratching at one or both ears, sometimes to the point of skin damage^{2, 5}
Odour from the ear canal⁵
Discharge, often black, brown or yellow, and waxy, gooey or crusted^{4, 8}
Redness, swelling, or pain when the ear is touched⁵

Signs that suggest the infection may be deeper

If the middle or inner ear is involved, the cat can look unsteady, as though the room has tilted.

Head tilt, stumbling, circling, falling, or abnormal eye movements (nystagmus)^{6, 7}
Reduced hearing on the affected side^{1, 6}
Facial nerve signs, for example drooping on one side of the face, drooling, or difficulty eating⁶

When to see a vet urgently

Arrange prompt veterinary care if you notice any of the following.

Head tilt, loss of balance, falling, or rolling⁶
Marked pain, swelling, bleeding, or a rapidly worsening ear
Facial droop, drooling, or trouble eating⁶
Symptoms lasting more than a day or two, or returning after previous treatment

How vets diagnose the cause

A useful ear exam is more than a quick look. Vets typically combine a few steps.

Otoscopy, looking down the ear canal and checking the eardrum⁴
Cytology, a microscope check of ear debris for mites, yeast and bacteria⁵
Further tests when needed, such as culture, and imaging (CT or MRI) if middle or inner ear disease is suspected or the problem will not resolve^{1, 5}

This step matters because treatment is not interchangeable. Some products are unsafe if the eardrum is ruptured, and leftover drops from a previous episode can mask the signs while the underlying problem carries on.⁴

Treatment options

Treatment depends on what is driving the inflammation and which organisms are present. Many cats improve quickly once the canal is properly cleared and the right medication is chosen.

Cleaning, often the first step

Removing wax and debris reduces irritation and lets medication reach the skin. Your vet may clean the ears in the clinic. Some cats need gentle sedation if the ear is very painful or the canal is narrow and swollen.⁵

Targeted medication

Mite treatment with topical or systemic parasiticides if mites are found or strongly suspected, usually paired with cleaning and treatment of in-contact animals as advised by your vet.³
Antifungal or antibiotic ear drops for yeast and bacterial otitis, chosen on the basis of the exam and cytology results.^{4, 5}
Anti-inflammatory medication to ease swelling and pain when indicated, and to help open the canal so it can drain and heal.⁵

When surgery is considered

Surgery is not a routine treatment for simple otitis externa in cats. It may be discussed when there is an ongoing structural problem such as a polyp, chronic disease that will not respond to medical management, or complications affecting the middle ear that need a more direct approach.^{1, 6}

Home care: what helps and what to avoid

What tends to help

Give medication exactly as prescribed, for the full course, even if the ear looks better early.
Return for rechecks if your vet recommends them. Ears can look calm on the surface while infection lingers deeper in the canal.⁵

What to avoid

Do not put random liquids into the ear, home remedies included, unless your vet has confirmed the eardrum is intact and advised a specific product.⁴
Avoid cotton buds deep in the canal. They can pack debris further in and irritate fragile skin.
Do not assume black discharge always means mites. Yeast and bacteria can look much the same.⁴

Prevention and recurrence

Some cats get a single episode and never see it again. Others recur because the trigger is still in place.

Parasite control as recommended by your vet helps reduce mite risk, especially in multi-cat homes or cats with outdoor contact.³
Address underlying skin disease, including allergy, if your cat has repeated ear problems. Controlling the bigger picture often quietens the ears.⁷
Follow-up matters for chronic or recurring cases, where middle ear involvement can keep the cycle going.^{1, 6}

Possible complications

Untreated or poorly controlled otitis can extend from the outer ear to the middle and inner ear. In severe cases cats can develop hearing loss and vestibular signs, meaning balance problems, and facial nerve involvement can occur with deeper ear disease. That is the reason timely treatment matters.^{1, 2, 6}

Common questions

Is "ear canker" the same as ear mites?

Not exactly. Ear mites are a common cause of otitis in cats, but yeast, bacteria, allergy and other conditions can look similar from the outside. A vet check, often including microscopy of ear debris, is the quickest way to tell them apart.^{3, 4}

Can I treat it with over-the-counter ear drops?

Treating blindly is risky. Different infections need different medications, and some products should not be used if the eardrum is damaged. Cats also tolerate ear pain poorly, so a quick, accurate diagnosis usually saves time, and scratching, in the long run.^{4, 5}

Why does my cat keep getting ear infections?

Recurring otitis often means the underlying driver has not been controlled. Common ones are mites in multi-cat environments, allergy or skin disease, or disease involving the middle ear. Your vet may recommend follow-up tests if it keeps returning.^{1, 7}

References

Sophie Kininmonth

Dog lover and writer at My Pets Australia, sharing practical breed guides and care advice for Australian pet owners.