Otitis Externa in Dogs
Inflammation of the external ear canal and one of the most common presenting complaints in small-animal practice, often with an underlying allergic cause.
Overview
Otitis externa is usually multifactorial: primary causes like allergies (atopic dermatitis, food allergy) or parasites set up the initial inflammation, predisposing factors like ear conformation and excess moisture make it more likely, and perpetuating factors like chronic tissue changes and secondary yeast or bacterial overgrowth keep it going. Addressing only the secondary infection without the underlying primary cause commonly leads to recurrence.
Clinical signs
- Head shaking and ear scratching
- Malodor from the ear canal
- Erythema and discharge, which may be ceruminous or purulent
- Pain on palpation of the ear canal
- In chronic cases, canal stenosis or calcification
Diagnosis
- Otoscopic examination of the ear canal and eardrum
- Cytology of ear discharge to identify bacteria, yeast, or parasites such as Otodectes
- Culture and sensitivity testing in chronic or antibiotic-resistant cases
- Work-up for underlying allergic disease in recurrent cases
Treatment
- Thorough ear cleaning appropriate to the underlying cause
- Topical medication, often a combination antibiotic/antifungal/anti-inflammatory preparation
- Addressing the underlying cause - allergy management, parasite treatment, or dietary trial as indicated
- Surgical options such as lateral ear resection or total ear canal ablation in severe, chronic, end-stage cases
Prognosis
Good with appropriate treatment when the underlying cause is identified and managed. Recurrence is common if the primary cause, most often an underlying allergy, is not addressed.
This page is general reference information for educational purposes. It is not a substitute for an individual clinical assessment, current formulary guidance, or the judgment of a licensed veterinarian treating a specific patient.
Frequently asked questions
Why do dogs get recurring ear infections?
Recurrence is usually a sign that an underlying primary cause, most commonly an allergy (environmental or food-related), hasn't been identified or addressed. Treating only the infection each time without addressing the underlying trigger tends to lead to a repeating cycle.
Are certain breeds more prone to ear infections?
Yes - breeds with floppy ears or hairy ear canals, and breeds prone to allergies, are generally at higher risk due to reduced air circulation and moisture retention in the ear canal.