Ear Canker otitis in Cats

Most people land on “ear canker” because their cat’s ears suddenly smell wrong, look messy, or the cat won’t stop shaking its head and scratching. Sometimes it’s just irritation in the outer ear canal. Other times it’s the first sign of mites, yeast, bacteria, or a deeper infection that can affect balance and hearing if it’s allowed to smoulder on.^{1, 2}

Veterinarians usually call this problem otitis (ear inflammation/infection). “Ear canker” is an older, informal term people still use for sore, inflamed ears with heavy wax and debris. The safest approach is to treat it as a symptom, not a diagnosis, and work out the cause before putting anything into the ear.^{3, 4}

What “ear canker” means in cats

In cats, “ear canker” most often refers to otitis externa: inflammation of the outer ear canal. The canal becomes warm, swollen, and reactive, and it starts producing more wax and discharge. That debris traps moisture and irritates the skin further, creating a tidy habitat for secondary infection.^{2, 5}

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

Common causes (and why the cause matters)

Otitis is rarely “just one thing”. Often there’s an underlying trigger, plus a secondary overgrowth of bacteria or yeast. The same-looking discharge can come from different causes, and the wrong drops can make things worse (especially if the eardrum is 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 often 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 (more commonly linked with middle-ear disease in cats), 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/yellow; may be 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 may look unsteady, as if the world 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, difficulty eating)⁶

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 persisting more than a day or two, or recurring after previous treatment

How vets diagnose the cause

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

• Otoscopy (looking down the ear canal, and checking the eardrum)⁴
• Cytology (microscope check of ear debris for mites, yeast, and bacteria)⁵
• Further tests when needed, such as culture, and imaging (CT/MRI) if middle/inner ear disease is suspected or the problem won’t resolve^{1, 5}

This step matters because treatment is not interchangeable. Some products are unsafe if the eardrum is ruptured, and “leftover drops” can mask signs while the underlying problem continues.⁴

Treatment options (what’s commonly involved)

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

Cleaning (often the first step)

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

Targeted medication

• Mite treatment (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 and/or antibiotic ear drops for yeast and bacterial otitis, selected based on 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’s an ongoing structural problem (such as a polyp), chronic disease that won’t respond to medical management, or complications affecting the middle ear that require 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 (including home remedies) 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.
• Don’t assume “black discharge” always means mites; yeast and bacteria can look similar.⁴

Prevention and recurrence

Some cats get a single episode and never see it again. Others recur because the trigger remains 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 (why timely treatment matters)

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 (balance problems). Facial nerve involvement can also occur with deeper ear disease.^{1, 2, 6}

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?

It’s risky to treat blindly. Different infections need different medications, and some products shouldn’t 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 hasn’t been controlled—commonly mites in multi-cat environments, allergy/skin disease, or disease involving the middle ear. Your vet may recommend follow-up tests if it keeps returning.^{1, 7}

References

1. Cornell Feline Health Center (Cornell University): Otitis
2. Cornell Feline Health Center (Cornell University): Ear mites (Otodectes cynotis)
3. VCA Animal Hospitals: Ear infections in cats (otitis externa)
4. Merck Veterinary Manual (Pet Owner Version): Otitis externa in cats
5. MSD Veterinary Manual (Professional Version): Otitis externa in animals
6. MSD Veterinary Manual (Professional Version): Otitis media and interna in animals
7. VCA Animal Hospitals: Inner ear infection (otitis interna) in cats
8. The Animal Medical Center: Ear infections in pets (causes, signs, treatments)