Health & vet care
Dog Ear Infection: Signs, Causes and When to See a Vet
A dog ear infection usually shows as head shaking, scratching at the ear, a bad smell, redness, and brown, black, or yellow discharge. Most are infections of the outer ear canal, and allergies are often the reason they keep coming back. Ear infections are painful and do not clear up on their own, so book a vet visit rather than trying home remedies.
By Matt GarnettUpdated November 13, 20264 min read3 sources
What it usually means
A dog's ear canal is long and L-shaped, so it traps moisture, wax, and debris. When the lining becomes inflamed, bacteria and yeast that normally live there in small numbers can overgrow. Vets call this otitis externa, and it is one of the most common reasons dogs are brought to a clinic.
The trigger is often something underneath. Allergies, to things in the environment or to food, are the most common driver of repeat infections. Other causes include ear mites, especially in puppies, trapped water after swimming or bathing, grass seeds or other objects lodged in the canal, and hormone conditions such as low thyroid function. Floppy, hairy-eared breeds such as Cocker Spaniels and Poodles are prone to them.
Signs of an ear infection in dogs
Watch for head shaking, scratching or rubbing an ear along the floor, a yeasty or sour smell, and redness or swelling inside the ear flap. Discharge may be dark brown, black, yellow, or green, and crusts or scabs can form around the opening. Many dogs flinch or yelp when the ear is touched.
Some dogs tilt their head toward the sore side. A swollen, puffy ear flap, which feels like a soft pillow, can be an aural hematoma, a blood blister caused by violent head shaking. It needs a vet as well, and it is a sign the ear has been bothering your dog for a while.
When to call your vet today
Book an appointment as soon as you notice signs, ideally within a day or two. The vet needs to see inside the canal and look at the discharge under a microscope to know whether bacteria, yeast, or mites are involved, because each needs a different treatment. Guessing often makes the problem last longer.
Call the same day if your dog is in obvious pain, will not let you touch the ear, has a swollen ear flap, or has had several infections already this year. Recurring infections are a sign that the underlying cause, often an allergy, has not been dealt with yet.
When it's an emergency
Seek urgent care if your dog suddenly loses balance, walks in circles, tilts their head sharply, has flicking eye movements, or seems unable to stand. These signs can mean the infection has reached the middle or inner ear, which affects balance, or that something else is affecting the nervous system.
Also go promptly if one side of the face droops, if there is a lot of bleeding from the ear, or if your dog is very lethargic or stops eating. Deep infections can damage the eardrum and, in some cases, cause permanent hearing loss.
What you can safely do at home
Until your vet sees your dog, gently wipe away discharge from the outer ear flap with a soft cloth, and stop your dog from swimming. Do not push cotton swabs into the canal, and do not pour in vinegar, hydrogen peroxide, oils, or leftover drops from a previous infection. Some products can harm a ruptured eardrum, and home remedies can worsen swelling.
Once your vet has diagnosed and treated the infection, they may show you how to clean the ears with a cleaner they choose. Finish the whole course of treatment, even if your dog seems better, and go back for the recheck, because an infection that looks gone can still be there.
What the vet will likely check
The vet will look down the canal with an otoscope to check the eardrum and look for objects or masses, then take a swab of the discharge to examine under a microscope. If the ear is very sore, your dog may need sedation for a proper look and a thorough cleaning.
For dogs with repeated infections, the vet may suggest a culture to choose the right medicine, and tests or food trials to look for allergies or thyroid disease. Some long-standing cases take weeks to months to bring under control and need ongoing management.
Preventing ear infections
Check your dog's ears weekly, for example while you go over the coat with your usual dog brushes. A healthy ear is pale pink, with little wax and no strong smell. Dry the ears gently after baths and swimming. In floppy-eared or hairy-eared breeds, ask your groomer or vet whether the hair around the opening should be trimmed.
If your dog has allergies, working with your vet to control them is the single best way to reduce ear infections. Keep up with parasite prevention, which helps with mites, and use only the ear cleaner your vet recommends, at the frequency they suggest.
This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.
Common questions
Will a dog ear infection go away on its own?
Rarely. Ear infections usually get worse without treatment and can spread deeper into the ear. Your vet needs to identify whether bacteria, yeast, or mites are involved to choose a treatment that works.
What does a dog ear infection smell like?
Many owners describe a yeasty, musty, or sour smell, and some infections smell much stronger. Any new bad smell from your dog's ear is worth a vet visit, especially with scratching or discharge.
Can I clean my dog's infected ear at home?
Wipe only the outer flap until your vet has looked inside. If the eardrum is damaged, some cleaners and drops can cause harm. Your vet will show you which cleaner to use once it is safe.
Why does my dog keep getting ear infections?
Repeat ear infections usually have an underlying cause, most often allergies, but also ear shape, trapped moisture, or thyroid disease. Ask your vet about finding and treating the cause, not just each infection.
Sources we checked
This guide is general information, not veterinary advice. If your pet is unwell or injured, contact your veterinarian.
