What Is Otitis Externa?
Otitis externa is inflammation of the external ear canal — the tube from the outer ear opening down to the eardrum. It is one of the most common reasons dogs (and many cats) visit US veterinary clinics. The canal becomes red, itchy, painful, and often filled with wax, debris, or discharge.
Otitis externa is usually a symptom complex with underlying drivers: allergies (including atopic dermatitis and food triggers), moisture after swimming, ear conformation (floppy ears, hairy canals), parasites (ear mites more often in cats/young pets), foreign bodies (foxtails), polyps, hormonal disease, or over-cleaning that irritates skin. Yeast and bacteria often overgrow secondarily once the canal environment changes — treating only the germs without the underlying cause is why ear problems keep coming back.
Why it matters
Uncontrolled otitis externa is painful and can progress toward middle-ear involvement or chronic canal changes that need surgery. Early exam, correct medication, and allergy/moisture control save pets months of head-shaking misery.
Signs Owners Notice
- Head shaking, ear scratching, or rubbing the face on furniture
- Redness, swelling, or odor from the ear
- Dark wax, yellow/green discharge, or crusting
- Pain when the ear is touched; irritability
- Head tilt in more severe or middle-ear cases
- Hearing seeming reduced during heavy debris buildup
Some pets have quiet, smelly ears with little dramatic shaking — smell and residue still count. Bilateral (both ears) disease often points toward allergies; a sudden one-sided flare can suggest a foxtail, polyp, or localized trauma.
Diagnosis and Treatment
A veterinarian examines the canal (often with an otoscope), checks that the eardrum is intact when possible, and reviews cytology — microscopic look at discharge to see yeast, bacteria, or inflammatory cells. Culture may be used for stubborn or resistant infections. Allergy history, swimming habits, and prior steroid/antibiotic use shape the plan.
Treatment commonly includes veterinary ear cleaners and prescription topical medications (antibacterial, antifungal, and/or anti-inflammatory components). Oral medicines or steroids are sometimes added. Never pour leftover drops, alcohol, or hydrogen peroxide into a painful ear without guidance — you can worsen damage if the eardrum is ruptured. Chronic or end-stage canals may need advanced imaging or surgical options discussed with a specialist.
Prevention and Everyday Tips
- Dry ears gently after swimming or baths; ask your vet before using drying solutions.
- Treat underlying allergies — recurrent otitis externa is often an allergy story.
- Use only cleaner products your veterinarian recommends, on the schedule they set.
- Keep routine grooming from packing hair/wax deeper into already inflamed canals.
- Return for rechecks when asked — “looks better” is not the same as cytology-clear.
When to see a vet
Book soon for odor, discharge, constant scratching, or pain on ear touch. Seek urgent care for sudden head tilt, balance loss, facial asymmetry, or severe pain — middle/inner ear involvement needs prompt attention.
Key Takeaways
- Otitis externa is external ear canal inflammation — common, painful, and often allergy- or moisture-related.
- Cytology-guided medication beats guessing with old drops.
- Preventing repeats means fixing the underlying cause, not only killing yeast or bacteria once.
FAQ
Is otitis externa the same as ear mites?
Ear mites can cause otitis externa, especially in cats and young animals, but many dog ear infections are yeast/bacterial overgrowth driven by allergies or moisture — not mites.
Can I clean my dog’s ears every day?
Over-cleaning can irritate canals. Follow your veterinarian’s frequency; inflamed ears need a treatment plan, not endless cotton-ball sessions.
Will diet changes help?
If food allergy is a driver, a properly run elimination diet under veterinary guidance can reduce ear flares. Do not randomly swap foods during an acute painful infection without a vet visit first.