The ear canal carries sound to the eardrum. The most common disorder of this canal in dogs is otitis externa—inflammation of the ear canal’s lining.
Signs include head shaking, foul odor, skin redness, swelling, scratching, ear discharge, and scaly skin. The ear can be painful or itchy. One or both ears can be affected, and signs can be sudden or ongoing.
Otitis externa can be caused directly by parasites, objects stuck in the ear canal, allergies, infection with bacteria or yeasts, or middle ear infections. The shape of the pinna or ear canal can make some dogs more likely to get otitis externa. Identifying all possible causes is essential. Unless every cause is treated, the condition often returns.
A detailed history and full physical and skin exam provide clues about the cause. The ear flaps and nearby areas might show signs of self-trauma, redness, and skin changes. Deformed ear flaps, abnormal growths in the canal, and head shaking suggest chronic discomfort.
A veterinarian will typically examine the ear with a special scope called an otoscope. This examination might require sedation or anesthesia if the ear is painful or blocked. Looking into the canal with the otoscope helps the vet find foreign objects, built-up debris, parasites, and damaged or abnormal eardrums. During this procedure, vets will often take samples of ear discharge to culture or to examine under the microscope.
The vet may take a smear of discharge with a cotton swab to quickly show whether bacteria, yeast, or parasites are present. Normal ears contain small numbers of harmless microbes that can overgrow when the ear environment changes. A dark discharge often indicates yeast or parasites but can also appear with bacterial or mixed infections. The vet will check ear discharge for ear mite eggs, larvae, or adults.
Additional tests—allergy tests, ringworm tests, skin biopsies, or x-rays—might be needed for chronic or one-sided inflammation or when middle-ear involvement is suspected.
Treatment
Treatment requires finding and correcting underlying causes and relieving pain. Hair around the ear is usually clipped for better cleaning and treatment. Hair inside the ear canal can be removed under anesthesia when needed.
Topical medications (applied to the skin) can be inactivated by discharge or wax, so vets usually clean and dry the ear before treatment. Dogs with painful ears often need anesthesia for proper cleaning. Follow your vet’s instructions for home cleaning.
Ideally, topical medication should coat the canal lining as a thin film. Medication given by mouth or injection might be added for long-term inflammation or suspected middle-ear inflammation. Most ear drops combine antibiotics, antifungals, and anti-inflammatories, and your vet will choose an appropriate product.
Avoid irritating home remedies (like vinegar mixtures) because they can worsen swelling and secretions and increase infection risk. Even products normally safe in healthy ears can irritate inflamed ears. Powders used after plucking hair can form irritating masses and shouldn't be used.
Severe bacterial infection often needs antibiotics plus anti-inflammatories to decrease discharge, pain, swelling, and secretions. Recurring bacterial infections and ear mite infestations may be treated with topical products that combat bacteria and parasites.
Treatment must continue until the infection is fully cleared. Dogs with bacterial and yeast infections usually need repeated veterinary checkups until no infection shows, often 2–4 weeks. Long-term cases can take months, and some dogs need lifelong treatment. Follow your veterinarian’s program fully for the best outcome.
Preventive Care
Preventing outer ear inflammation involves regular ear checks for temperature change, skin discoloration, sudden presence of moisture, or other changes. Prompt veterinary attention is needed when changes appear. If your dog often develops ear infections, your vet may ask you to clean the dog's ears regularly. If you clean your dog's ears, be sure to follow your vet's instructions carefully.
Your vet can show you the proper technique. You might start off cleaning your dog's ears once a day but then decrease to once or twice a week for maintenance. Keep ear canals dry and well ventilated. In some cases, trimming or plucking hair near the ear canal improves airflow and decreases humidity, but consult your vet before removing hair.
Avoid getting water in the ears during bathing. Use drying agents as recommended by your veterinarian for dogs that swim frequently.
