Dog Ear Infection: Symptoms, Causes, Treatment & Prevention 2026
Dog ear infections — medically called otitis — are one of the top reasons pet owners visit the vet, affecting roughly 20% of dogs. They can range from mildly itchy to intensely painful if untreated. Understanding the causes, recognising symptoms early, and knowing when to see a vet can save your dog from unnecessary suffering.
What Is a Dog Ear Infection?
A dog ear infection is an inflammation of the ear canal, classified by location: Otitis externa (outer ear — most common), otitis media (middle ear), and otitis interna (inner ear). Most infections are caused by an overgrowth of yeast (Malassezia) or bacteria (Staphylococcus, Pseudomonas).
Dogs with floppy ears — Cocker Spaniels, Basset Hounds, Labrador Retrievers, Poodles — are most predisposed because the ear flap traps heat and moisture, creating an ideal environment for microbial growth. Dogs who swim frequently or have allergies are also at higher risk.
Signs and Symptoms of Dog Ear Infection
Recognising a dog ear infection early is crucial. Common signs include:
- Head shaking or tilting to one side
- Scratching at the ear or rubbing it on furniture
- Redness, swelling, or warmth inside the ear
- Dark, waxy, or coffee-ground-like discharge
- Foul or yeasty odour from the ear
- Pain when the ear is touched
- Loss of balance or stumbling (severe cases)
- Hearing loss (chronic cases)
Yeast infections tend to produce brownish discharge with a musty smell. Bacterial infections often produce a pungent odour; discharge may be yellow, green, or bloody. Mixed infections show characteristics of both.
In puppies, ear infections can resemble ear mites, which also cause dark debris and itching. Your vet can distinguish between them under a microscope.
Causes of Dog Ear Infections
The root cause of most ear infections is an underlying issue disrupting the ear’s natural environment:
- Allergies — environmental or food allergies are the number one trigger for chronic ear infections; immune inflammation allows yeast and bacteria to overgrow
- Moisture — water trapped after swimming or bathing creates a breeding ground
- Foreign bodies — grass seeds, dirt, or debris lodged in the ear canal
- Ear mites — common in puppies; parasites trigger secondary infections
- Hormonal imbalances — hypothyroidism and Cushing’s disease affect skin and ear health
- Excessive ear cleaning or plucking — disrupts the ear’s microbiome and causes irritation
- Narrow or hairy ear canals — structural predisposition in certain breeds
Identifying the underlying cause is essential for preventing recurrence. Without treating the trigger — especially allergies — most ear infections return within weeks to months.
How Vets Diagnose and Treat Dog Ear Infections
Your vet will begin with an otoscopic examination and take a cytology swab to identify yeast, bacteria, or both under a microscope. For chronic or severe cases, a culture and sensitivity test determines which antibiotic will be most effective — especially important if Pseudomonas (a difficult bacterium) is involved.
Treatment options include:
- Ear cleaning — a thorough veterinary clean is the first step; continued with vet-prescribed cleaner at home
- Topical ear drops — combination drops containing antifungal, antibiotic, and anti-inflammatory agents
- Oral medications — for deep or resistant infections, oral antifungals or antibiotics
- One-time in-clinic treatments — products like Claro or Osurnia applied once and lasting 30 days
- Surgery (TECA) — Total Ear Canal Ablation is a last resort for end-stage chronic ear disease
Never use cotton swabs (Q-tips) inside a dog’s ear canal — they push debris deeper and can damage the eardrum.
How to Prevent Dog Ear Infections
Prevention is far better than treatment, especially for prone dogs:
- Dry ears after swimming or bathing — use a soft cloth or vet-approved drying solution
- Regular gentle cleaning — once weekly or as recommended with a vet-approved cleaner; never over-clean
- Manage allergies — work with your vet to identify and control food or environmental allergens
- Keep ear hair trimmed — reduces moisture retention in hairy-eared breeds
- Routine vet checks — annual examinations catch early changes before they become infections
- Avoid harsh products — never use hydrogen peroxide, apple cider vinegar, or human ear drops in a dog’s ears
Dogs with allergies benefit greatly from a systematic management plan. If your dog gets more than two or three ear infections per year, ask for a referral to a veterinary dermatologist.