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Medical Condition🐕 Dogs🐈 Catsdermatological

Otitis Externa

🗣️ Pronounced:oh-TY-tis ek-STER-nuh
In One Sentence (Plain English)

Acute or chronic inflammation of the external ear canal, commonly complicated by secondary bacterial or yeast overgrowth.

Editorial Status: Verified from peer-reviewed veterinary sources (v1.0)
Updated: 2026-01-15

💬 In Plain English

A dog’s ear canal is L-shaped, having both a vertical and a horizontal canal before reaching the eardrum. When the delicate skin lining the canal becomes inflamed—most commonly due to underlying environmental or food allergies—the warm, dark, humid environment allows normal skin yeast (Malassezia) or bacteria to multiply out of control. Dogs shake their heads violently, scratch at their ears, hold their head tilted, and produce dark, waxy, foul-smelling ear discharge.

🔬 Clinical & Technical Depth

For Vets & Technicians

Formal Clinical Definition

Inflammation of the epidermis of the pinna and external auditory meatus down to the tympanic membrane, categorized into primary predisposing factors (allergies, foreign bodies) and secondary perpetuating microbial infections (yeast, staphylococci, Pseudomonas).

Why Veterinarians Use It

Veterinarians diagnose otitis externa using otoscopy and in-house cytology to determine which specific microbes are present and ensure the eardrum is intact.

Clinical Context Encountered

One of the top three most frequent reasons dogs visit veterinary hospitals, especially floppy-eared breeds or dogs that swim frequently.

Clinical Reference Guide (Medical Condition)

Severity
Emergency StatusNon-Emergency Care
🚨 Red Flag Warnings (When to Contact an Emergency Vet)
  • •Violent head shaking can rupture blood vessels in the ear flap, creating a painful, swollen aural hematoma that often requires surgical drainage.
  • •Head tilt paired with circling or rapid eye twitching (nystagmus) suggests infection has breached the eardrum into the inner ear (otitis interna).

❓ Questions to Ask Your Veterinarian

Take these actionable questions with you to your next clinic visit or appointment:

  • 1Did ear cytology show yeast, rod bacteria, or cocci bacteria?
  • 2Is the tympanic membrane (eardrum) intact, or is it ruptured?
  • 3Could underlying underlying atopic dermatitis (environmental allergy) or food allergy be causing recurrent flare-ups?
  • 4How should I properly clean the ear canal without pushing debris deeper?

Academic & Clinical References