Otitis Externa in Dogs: Welfare and Prevention
Why Dogs Get Ear Infections
Otitis externa (OE) is inflammation of the external ear canal, usually involving bacterial and/or yeast overgrowth. Predisposing factors include: pendulous ear conformation (Cocker Spaniels, Bassett Hounds) reducing ventilation; hair-filled ear canals; narrow canals (Shar Peis, Chow Chows); allergic skin disease (atopy, food allergy — the most common underlying cause); increased moisture (swimming dogs); foreign bodies (grass seeds); and hypothyroidism. Perpetuating factors (Pseudomonas infection, otitis media) maintain disease once established.
Welfare Impact
Otitis externa causes significant pain and discomfort: head shaking, scratching at the ear, rubbing the head on surfaces, tilting the head, and vocalisation on ear manipulation. Chronic otitis causes progressive changes (proliferative tissue, narrowing of the canal, calcification) that are painful and eventually irreversible. Dogs with chronic otitis may show behavioural changes (irritability, avoidance of handling) reflecting ongoing pain. Inadequately treated acute OE becomes chronic, dramatically worsening welfare.
Diagnosis
Full otoscopic examination (ideally under sedation in painful ears) assesses the tympanic membrane, canal condition, and identifies foreign bodies. Cytology (ear swab stained with Diff-Quik or similar) identifies the type and relative amount of organisms — the most important guide to treatment selection. Culture and sensitivity testing of ears not responding to initial treatment identifies resistant organisms (particularly Pseudomonas). Underlying disease (allergy, hypothyroidism) must be identified and managed.
Treatment
Cleaning (ceruminolytic agents to soften and remove debris, then gentle flushing) before topical medication application is essential. Topical preparations combine antibiotics (neomycin, gentamicin, marbofloxacin, tobramycin), antifungals (clotrimazole, miconazole), and corticosteroids (reduce inflammation and pruritus). Duration: minimum 7-14 days; chronic cases may require 3-4 weeks. Pain relief (NSAIDs, analgesics) for acutely painful ears is an essential welfare measure. Systemic antibiotics for otitis media.
Long-term Prevention
Long-term prevention of recurrent OE focuses on managing underlying disease: allergy management (hypoallergenic diet trial, immunotherapy, anti-itch medications) dramatically reduces OE frequency in allergic dogs. Regular ear cleaning (frequency depends on individual ear, 1-4 times monthly) with appropriate ceruminolytic solutions maintains canal health. Post-swimming ear drying reduces moisture. In dogs with recurrent OE despite management, surgical widening of the ear canal opening (lateral wall resection) improves ventilation and treatment access.