What Is a Cat Ear Infection?
A cat ear infection — medically termed otitis — is an inflammatory condition of the ear canal. Outer ear infections (otitis externa) are most common; cats can also develop middle (otitis media) and inner ear infections (otitis interna). Causes include bacteria, yeast (Malassezia), ear mites, foreign bodies, polyps, or tumors. Identifying the specific cause is essential for effective treatment. Ear infections are unlikely to resolve on their own and can worsen significantly without treatment.
Signs and Symptoms
Head shaking — one of the first and most noticeable signs. Scratching at the ear — sometimes causing hair loss around the ear. Odor — yeasty, cheesy, or foul smell. Discharge — dark brown/black (mites or yeast), yellowish/green (bacterial), or blood-tinged. Redness and swelling of the ear canal and pinna. Sensitivity — crying or pulling away when ears are touched. Head tilt — suggests middle or inner ear involvement. Loss of balance — inner ear infections cause vestibular signs. Any combination of these signs warrants a vet visit.
Common Causes
Ear mites (Otodectes cynotis) — most common in young and outdoor cats; produce dark, coffee-ground-like debris; highly contagious between cats and dogs. Bacterial infections — usually secondary to mites, allergies, or trauma; common bacteria include Staphylococcus and Pseudomonas. Yeast infections (Malassezia) — dark brownish discharge with musty odor; often secondary to allergies or chronic moisture. Allergies — food or environmental; the most common underlying cause of recurrent infections. Polyps and foreign bodies — block drainage and trigger infection.
Veterinary Diagnosis and Treatment
Your vet will use an otoscope and take swabs for cytology to identify the infection type. Treatment: Ear mites: spot-on antiparasiticides (selamectin/Revolution); treat all pets simultaneously. Bacterial: antibiotic ear drops for the specific bacteria identified. Yeast: antifungal ear drops (clotrimazole, miconazole, nystatin). Polyps: surgical removal. Chronic recurrent infections: allergy testing or dietary elimination trials to identify the root cause.
Home Care and Prevention
Inspect ears weekly — normal ears are pink, odor-free, with minimal waxy discharge. If cleaning is recommended, use vet-approved cleaner on a cotton ball — never swabs inside the canal. Complete the full treatment course (1–3 weeks) even when symptoms improve; stopping early is a leading cause of recurrence. Treat all pets if mites are the culprit. Address underlying allergies to prevent chronic recurrence.
Can a cat ear infection go away on its own?
Very rarely. Bacterial, yeast, and mite infections won’t resolve without appropriate treatment. Without treatment, infections typically worsen and can spread to the middle or inner ear, potentially causing permanent hearing loss.
How long does it take for a cat ear infection to clear up?
With appropriate treatment, most uncomplicated outer ear infections improve within 1–2 weeks. Full resolution typically occurs within 2–4 weeks. Chronic or deep infections may take longer.
Can I use home remedies for my cat’s ear infection?
Olive oil, vinegar, and hydrogen peroxide should not be used in cat ears without vet guidance — these can irritate or damage inflamed tissue. Only use products specifically recommended or prescribed by your vet.
Are cat ear infections contagious to humans?
Ear mites can rarely transfer to humans but don’t establish permanent infestations. Bacterial and yeast infections are not typically transmissible to people. Always wash hands after handling an infected cat’s ears.
How do I tell the difference between ear mites and a bacterial ear infection?
Ear mites produce dark, dry, coffee-ground-like debris with intense itching. Bacterial infections produce moist yellowish/greenish discharge with a foul odor. Yeast produces dark brownish discharge with a musty smell. Only vet cytology can definitively identify the cause — they often overlap.