CONDITION

Otitis Externa in Cats

Why this matters now

Otitis externa in cats can develop at any age, though certain causes predominate at different life stages. Ear mite infestations are particularly common in kittens and young cats, while older cats may develop ear problems secondary to allergies, polyps, or less commonly tumours. The condition may appear suddenly or develop gradually over weeks to months.

Without addressing underlying causes, feline otitis externa tends to recur or become chronic. What begins as mild inflammation can progress to involve deeper structures of the ear if left untreated. Chronic changes to the ear canal can make the condition increasingly difficult to manage over time.

Signals & patterns

Early signals

Head shaking or ear scratching

Cats may repeatedly shake their heads or scratch at their ears when experiencing early ear discomfort. Some cats become more resistant to having their ears touched.

Visible ear discharge

Dark, waxy, crumbly discharge often indicates ear mites, while other types of discharge may suggest bacterial or yeast infections. Any change from normal ear appearance warrants attention.

Odour from the ears

An unusual smell coming from one or both ears may indicate infection or excessive wax production.

Holding ears differently

A cat may hold an affected ear lower than usual or flatten it against the head more than normal.

Later signals

Head tilt

A persistent head tilt toward the affected side may develop, potentially indicating that inflammation has extended beyond the external ear canal.

Balance problems

Vestibular signs such as circling, falling, or coordination difficulties may occur if the middle or inner ear becomes involved.

Thickened, narrowed ear canal

Chronic inflammation can cause permanent changes to the ear canal structure, making it more difficult to examine and treat.

Click to read about the biological mechanisms

How this is usually investigated

Investigating feline otitis externa involves examining the ear canal and identifying both the current state of the ear and any underlying causes that need addressing.

Otoscopic examination

Purpose: Visual examination of the ear canal using a magnifying instrument with a light source to assess inflammation, discharge, foreign bodies, polyps, or the eardrum.
Considerations: Some cats require sedation for thorough examination, particularly if the ear is painful. Assessing eardrum integrity is important before certain treatments.

Ear swab cytology

Purpose: Microscopic examination of ear discharge to identify the types of organisms present—bacteria, yeast, or mites.
Considerations: Cytology helps guide treatment choices and can differentiate between different types of infection. It can also confirm ear mite infestation.

Bacterial culture and sensitivity

Purpose: Identifying specific bacteria and determining which antibiotics they respond to.
Considerations: May be recommended for recurrent or resistant infections, or when initial treatment has not resolved the problem.

Advanced imaging

Purpose: CT or MRI scans can evaluate the middle and inner ear, skull structures, and identify polyps or tumours.
Considerations: Recommended when there are vestibular signs, suspected middle ear involvement, or to plan surgical intervention for polyps.

Allergy investigation

Purpose: Identifying underlying allergic triggers if allergies are suspected as the primary cause.
Considerations: May involve dietary trials, environmental assessments, or intradermal testing to identify specific allergens.

Options & trade-offs

Managing feline otitis externa effectively requires addressing both the current ear condition and any underlying causes. Treatment approaches vary depending on the cause and severity.

Topical ear medications

Ear drops or ointments applied directly to the ear canal, typically containing combinations of anti-inflammatory, antimicrobial, and antifungal agents.

Trade-offs: Requires regular application over days to weeks. Some cats resist ear handling, making treatment challenging. Not all formulations are safe if the eardrum is ruptured.

Ear cleaning

Regular cleaning to remove debris and discharge, improving the environment for healing and medication effectiveness.

Trade-offs: Must be done carefully to avoid pushing material deeper or damaging delicate structures. Some cats require sedation for thorough cleaning.

Systemic medications

Oral or injectable medications when topical treatment alone is insufficient or when middle ear involvement is suspected.

Trade-offs: May be easier to administer than topical treatments for some cats. Systemic treatments carry their own considerations regarding side effects.

Surgical intervention

For ear polyps, tumours, or chronic severe cases, surgery may be considered to remove masses or address structural changes.

Trade-offs: Polyp removal often provides excellent outcomes, though regrowth is possible. More extensive surgery for chronic ear disease is a significant intervention.

Addressing underlying causes

Managing allergies, treating for mites in all contact animals, or addressing other primary factors.

Trade-offs: May require ongoing management for allergic conditions. Treating the underlying cause is essential for preventing recurrence.

Common misconceptions

Misconception:

"Ear mites only affect outdoor cats"

Reality:

While more common in cats with outdoor access or those from shelters, ear mites can affect any cat. They spread through close contact, so indoor-only cats can acquire them from new feline additions to the household.

Misconception:

"Dark ear wax always means infection"

Reality:

Cats normally produce some ear wax, and its colour can vary. While dark, crumbly discharge often suggests ear mites, not all dark-coloured ear debris indicates a problem. The amount, consistency, odour, and accompanying signs are all relevant.

Misconception:

"Ear problems in cats are always straightforward to treat"

Reality:

Unlike simple ear mite infestations that often respond well to treatment, other causes of feline otitis—such as polyps, allergies, or resistant infections—may require more complex investigation and management approaches.

If your cat shows signs of ear discomfort, observing whether it affects one or both ears can provide useful information. Noting any associated signs such as respiratory noise, nasal discharge, or balance changes can help build a complete picture. Completing full treatment courses and addressing all in-contact cats when mites are diagnosed helps prevent recurrence.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS