Ear infection (otitis externa) in the dog

What is otitis externa?

Otitis externa is an inflammation of the external ear canal. In dogs, the condition is rarely standalone: in the vast majority of cases, an underlying cause is responsible for the problem [1][2]. If you treat only the symptom without identifying that underlying cause, the complaints will return.

The PSPP model: four layers

Veterinary dermatologists use the PSPP system to categorise causes [2]:

All layers must be addressed for sustainable recovery. Treating a yeast infection while leaving a food allergy untreated does not structurally resolve the problem.

Which dogs are at higher risk?

A large UK study (2021) showed an annual prevalence of 7.3% in primary veterinary care [3]. Some breeds have a significantly higher risk compared with crossbreeds:

• Basset Hound — 5.9× increased risk
• Chinese Shar Pei — 3.4×
• Labradoodle — 2.95×
• Beagle — 2.5×
• Golden Retriever — 2.2×

This higher risk is associated with ear anatomy and predisposition to atopy [3].

What is proven to work?

Veterinary topical treatment is the first choice. Combination preparations containing an antimicrobial agent and a corticosteroid effectively reduce inflammation and infection [2]. Which agent is appropriate depends on cytology of the ear secretion: yeast overgrowth requires different agents than a bacterial infection. Without cytology, the choice is a guess.

If otitis media (middle ear inflammation) is suspected, systemic antibiotics following culture and sensitivity testing are necessary — topical treatment alone is insufficient in that case [2].

Home remedies: honesty about the evidence

For commonly used home remedies, the evidence is frankly insufficient:

• Vinegar (diluted or pure): no scientific evidence of efficacy in otitis externa in the dog; can further damage irritated skin [2].
• Coconut oil: no clinical evidence; can retain moisture in the ear canal and thereby promote infection [2].
• Other 'natural' ear drops: not investigated in controlled animal studies.

Use only veterinary-approved ear cleaning solutions for cleaning, and only if the veterinary surgeon has recommended this. Cleaning in the presence of a (nearly) perforated eardrum can cause serious damage.

Adjunctive ≠ replacement

If an allergy is the primary cause, dietary adjustments (elimination diet under veterinary supervision) or treatment of atopy can reduce the frequency of recurrence — but this is part of a veterinary allergological approach, not an alternative to it. Chronic or recurring cases always require additional allergological investigation [3].