Why Do My Dog’s Ears Smell Bad?

By Dr Duncan Houston

A new musty or unpleasant smell from an ear is a reason to look for a problem, not reach automatically for a stronger cleaner. The canal may already be inflamed and painful.

Quick Answer

Smelly ears commonly accompany otitis externa, inflammation of the outer ear canal, often with yeast or bacterial overgrowth. Allergies, parasites, moisture and foreign material can contribute. Arrange a veterinary examination for persistent odour, redness, discharge or head shaking, and avoid putting products into a painful ear before it is assessed.

What could be causing the smell?

Yeast and bacteria can multiply in an inflamed canal, but the underlying reason matters. Allergic skin disease commonly contributes to recurrent problems. A grass seed or other foreign body may cause sudden one-sided irritation. Mites are another possibility, although dark debris alone does not establish that diagnosis.

Smell descriptions such as cheesy or yeasty cannot reliably identify the organism. Wax colour is also insufficient to choose a drug. Repeatedly treating the apparent infection without addressing the cause can allow chronic thickening and narrowing of the canal.

How urgent is it?

What the vet checks

An ear examination assesses the canal, foreign material and, where visible, the eardrum. Microscopy of a sample helps distinguish yeast, bacteria and inflammatory cells. Some cases need culture, sedation for a comfortable examination or investigation of middle-ear disease. Recurrent episodes also warrant a skin and allergy review.

What to do before the appointment

1. Keep the ear dry and prevent rough scratching where possible.
2. Record which ear is affected, when it started and any swimming or grass exposure.
3. Tell the clinic what cleaners or medicines were already used.
4. Do not insert cotton buds or instruments into the canal.
5. Do not use vinegar, peroxide, alcohol, oils or leftover drops. An unsafe product may worsen pain or damage an ear with an abnormal eardrum.

When is this an emergency?

Balance problems, repeated falling, severe pain, facial changes or a dog who is markedly unwell need urgent assessment. Keep the dog away from stairs and do not flush the ear while arranging care.

Common mistakes

• Choosing antibiotics from the smell alone.
• Cleaning every healthy dog's ears weekly regardless of need.
• Stopping prescribed treatment without the planned review.
• Plucking or trimming deep ear hair at home during an inflamed episode.

Preventing recurrence

Follow the cleaning frequency and product recommended for your dog's ears. Manage underlying skin disease and review problems that repeatedly return after swimming. Regular gentle checks are useful; constant treatment of a healthy canal is not.

Frequently asked questions

Can I diagnose yeast by the smell?

No. Microscopic examination is much more useful, and mixed infections can occur.

Will cleaning alone cure it?

Not reliably. Inflammation, infection or a foreign body may require specific treatment.

Why does it keep coming back?

An unresolved underlying cause, incomplete response or chronic canal changes may be involved. Recheck rather than repeating the same bottle.

The goal is a comfortable healthy ear, not simply covering up the smell.

Further reading

• MSD: ear infections in dogs
• MSD: otitis externa
• MSD: middle and inner ear disease

For more practical guidance on caring for your dog, explore ASK A VET™. If your dog needs urgent treatment, contact your veterinary clinic directly.