dog with ear flipped open to show infection

How to Deal with a Dog Ear Infection

A head shake here, a little hind foot scratch there. But at its peak, a dog ear infection is pretty awful, as many pup parents out there can testify to. Red, swollen, painful ears that smell terrible and have nasty white, yellow, or brown gunk.

When they really get going, there’s nothing subtle about them and they can be really uncomfortable, even painful, for a pooch.

In this article, we’re going to go over the ins and outs of ear infections in dogs, including what causes them, what makes some of them so bad, treatment approaches, and most importantly, how to catch them early and prevent them at home.

But first, before we get down and dirty talking about red, swollen, gunky ears, let’s talk about what a dog’s ear is normally like and how it differs from our own.

It’s insidious and subtle at the start. 

dog laying down ears open

The Normal Ear Canal: A Brief Anatomy Lesson

I once had a human surgeon bring his dog in with an ear infection. Both ears were affected, practically swollen shut, with nasty crusty yellow debris covering the inner surface. At her older age of 10 years, this had never happened to her before, and he was convinced that something, like an earwig or piece of foreign material, was stuck down there, causing a reaction and infection and requested that I get a really thorough look.

I gave it my best attempt, but the poor dog’s ears were so painful, I could only get the otoscope about 1cm into the canal. He was not impressed when I informed him that I could see little other than inflamed ear tissue and pus, as he seemed to think that my brief superficial look should have been sufficient to see the whole canal.

This moment made me realize that many folks, even the best and brightest, like a human surgeon, have no idea how different a dog’s ear canal really is from a person’s.

Humans Vs Dogs: Ears

A person’s ear canal is relatively straight. If you insert an otoscope cone into it, you really don’t need to insert it far to be able to see the eardrum. And even in cases of painful ear infections, like my kids have had a few times, the cone can still be inserted without causing a lot of additional pain.

But a dog’s ear canal is actually very deep. It’s also “L” shaped, and has two parts to the outer canal. The first is the vertical canal, which you can partly see yourself as the dark hole that goes straight down. But the canal then makes an abrupt right angle turn in towards the head, ending at the eardrum.

Eardrum Vs Ear Canal

The eardrum separates the outer ear canal from the middle ear, which is a small chamber just on the other side of it. Just above the middle ear sit the bony structures of the inner ear, which are essentially inside the skull itself. These inner ear structures are responsible for hearing and balance.

To view the entire canal, a vet must insert an otoscope cone much longer than what is used for a person. First, down the vertical canal. Then the ear must be pulled down to try to flatten it out and insert the cone further to see the horizontal canal and the ear drum.

The beauty of a dog’s ear structure is that it’s all designed to amplify sound, which gives pups such amazing hearing. The downside to this incredible anatomy is that there’s a lot of dark, narrow space for moisture and debris to collect.

The other difference that makes ear infections in dogs unique from a person’s is that ear infections in people, at least in children, are focused more towards the level of the eardrum. The outer ear isn’t as painful and neither is most of the short, shallow ear canal.

But in a dog, the eardrum is often the least affected part of any but the worst infections. It’s the entire canal, including the skin of the outer ear that is affected. This makes the entire ear one big focal point of pain, sometimes so bad that the entire canal itself is swollen shut.

So imagine trying to insert that long otoscope cone down this entire inflamed and painful structure. 

What Causes Ear Infections?

We’ve established that the structure of the ear canal lends well to harboring and festering infections, but what leads to them in the first place?

There’s two main causes. We’ll start with the simplest first.

Water Makes for Wet Ears

That long, narrow ear canal with its angles and extra folds makes it the perfect environment for moisture to collect.

As we’ll talk about in more detail shortly, a dog’s ears, just like his skin as well as our own skin, play host to bacteria as well as fungal organisms. In normal levels, these symbiotic organisms actually keep out more harmful ones.

Warm, moist conditions can tip the scales in favor of bacterial and yeast growth, leading to a harmful overgrowth of these organisms. The body’s immune system working to tip the scales back into balance by attacking the bacteria and yeast, contributes to the redness, irritation, and itchiness a pup experiences.

Common scenarios that can contribute to excessive moisture include swimming and baths. It’s not uncommon a week or two after a few days swimming in the ocean or a thorough bath at the groomer to see a pup developing some itchy, stinky ears.

The nice thing about this underlying cause is that these infections tend to resolve well and they are preventable as long as we engage in the proper care after these water-borne activities, which we’ll talk about a little later on when we get to home care. 

girl washing her dog in bathtub


The second main cause of ear infections in dogs is actually the leading cause, especially in cases of recurrence when they happen over and over again. But while the term “allergy” is used quite often, this underlying cause of ear infections as well as skin infections in dogs is really quite a bit more complicated than some seasonal sniffles.

To understand what happens, it’s important to briefly understand how important a role the skin really plays, especially in dogs. Many don’t think of the skin as an actual organ, but it really is and has many important roles as a protective barrier against infectious organisms and allergens.

Importance of Skin

Those bacteria and yeast that live normally on the skin do so with restrictions, because the skin barrier still keeps them in check, preventing overgrowth. In turn, the presence of these organisms keep more harmful ones from setting up shop.

But if there’s any changes to that important barrier the skin provides, all bets are off. We can see invasion and overgrowth of not just harmful bacteria that the skin comes in contact with, but even the normal, symbiotic bacteria and yeast can start to cause problems.

Issues at the Skin

And this is essentially what happens with skin allergies in dogs. Many dogs are exposed to allergens everyday with no ill result. But in some dogs, their immune systems seek out and attack certain allergens. This sets off a complex inflammatory response that leads to breakages in that important skin barrier.

Because of how complex this process is, skin allergies in dogs should be thought of more as the condition called eczema in people. The most common form of eczema in people is called atopic dermatitis, which is exactly the same medical term we use for skin allergies in dogs.

In both dogs and people, atopic dermatitis involves the immune system responding to allergens, whether environmental or food-related, which in turn causes red, irritated and itchy skin. In dogs, we commonly see secondary skin and ear infections as a result of this break-down in the skin barrier. Most of the time, these infections are composed of the symbiotic yeast and bacteria overgrowing, but other more harmful bacteria sometimes like to join the party and make things worse.

Complicating Factors

Although these are the two main causes I see in practice, there are some less common causes most often diagnosed by veterinary dermatologists that can be seen.

There are other complicating factors varying from pup to pup that can contribute to or worsen ear infections, in addition to these underlying causes. Here’s a couple.

Stenotic Ear Canals

Stenosis is a technical term for abnormally narrow ear canals. This can be a normal variation in some dogs, or stenosis can occur and worsen over time with recurrent infections as the skin of the ear canal gets more thickened. Stenosis can lead to complete loss of air exposure to the ear canal, creating a pocketed environment of warmth and moisture, which bacteria and yeast love. Stenosis also makes it extremely difficult to examine or clean the ear canal.

Floppy Ears

Cocker Spaniels are the classic example of pups with long, floppy ears. Hounds, like Basset Hounds and Beagles, are a couple others. While adorable to be sure, the floppiness of the ears also closes them off to airflow, trapping warmth and moisture. Spaniels and hounds quite often develop chronic ear infections in part because of how their ears are shaped.

Excessively Hairy Ears

Dogs are covered in hair, and in some breeds, this extends to their ears. Poodles and poodle mixes like Goldendoodles, are classic breeds for having excessive hair covering their ear canals. This hair is often very curly and springy, trapping debris and moisture. In pups like these that develop chronic issues with their ears, I am an advocate of regular trimming of this hair at the groomer.

Environmental Conditions

If it’s excessively warm and humid outside, we can also see warmer, more humid conditions in the ear canal as well. Some areas of the world are like this year-round, but in more seasonal regions, this can be why we see more problems with ear infections during the spring, summer, and early fall.

Foreign Material

It’s uncommon, but I mention it because many pup parents, especially when encountering an ear infection for the first time, like the human surgeon I mentioned early on, might assume that something got stuck down in the ear.

On occasion, I have seen a stray hair or a piece of plant material, like a blade of grass or seed head, make its way down there. But for the most part, while we will see pups suddenly shaking their heads and scratching, we don’t tend to see the same severe changes encountered with typical ear infections and usually it’s only one side that’s affected. In fact, I tend to suspect a foreign body more if I have a dog experiencing irritation on one side only, with an otherwise almost normal appearance to the outer ear canal.

And earwigs? It’s largely a myth that they crawl into people’s ears, much less a dog’s.

How to Recognize an Ear Infection

A dermatologist I once worked with was fond of saying that while the skin is a very important organ, it’s not a very smart one. In response to any challenge, it gets thicker, redder, more irritated, and produces nasty stuff. If you’re an experienced pup parent, you’re probably familiar with these telltale signs.

The appearance of a dog ear infection can vary a little, but will always contain one or more of the following characteristics.


Often, the ear can appear red, which is medically termed “erythema”. This redness can range from just a mild change from normal, to as red as a tomato. This is caused by both the inflammatory changes in the skin to underlying allergens, as well as bacteria or yeast overgrowth. Some dogs, in addition to multiple environmental or food allergens, can also have an allergy to yeast organisms themselves, making their overgrowth put the immune system’s response into overdrive.


Debris amounts can vary, and usually the more debris that’s present, the longer the infection has been going on. Dark brown debris, while not exclusively the case, is more often associated with yeast infections. Infections caused exclusively by bacteria more often have a light brown to grey or white appearance. But don’t be fooled. Infections can often include both yeast and bacteria in varying amounts, and the type of infection can’t be predicted based on debris appearance alone.


I would say that when the outer ear appears crusted, that a bacterial infection is more often present. But again, it’s not uncommon to see some yeast mixed in these infections as well. Crusting is a definite sign that the all-important skin barrier is severely disrupted.

Thickened Skin

Because of inflammation and disruption of the skin barrier, sometimes the outer ear and the canal will appear diffusely swollen. This can happen acutely for sure, but we can also see a more chronic appearance of thickening called lichenification. The skin of the outer ear will take on a thickened, pebbly appearance, kind of like elephant skin. This is simply evidence that the ear has been struggling for some time.

Pee Yew Yuck

When bacterial or yeast growth really takes off, a foul odor often develops. Yeast has a damp, musty odor that’s unmistakable for those who have come to recognize it. This is sometimes one of the first abnormal signs a pup parent discovers in their poor pooch, as they get a whiff during some close cuddle time.

Itching and Scratching

This is also one of the most common signs pet parents notice. Scratching can occur with just an allergenic response to the ears being itchy and red, before an infection develops. But most often, by the time your pup starts shaking her head, scratching at her ears and rubbing them on the carpet, bacterial or yeast growth has already been building up.

How to Care for an Ear Infection at Home

Keep an Eye on the Ear

The first and foremost part of care at home for ear infections is to catch them as early as possible. Generally if you have an at risk pup, but there is no current infection, I advocate cleaning the ears once a week. This helps prevent debris accumulation and allows a regular good look to catch a problem before it goes too far.

Cleaning at Home

Regular ear cleaning can be very helpful, even if your pup isn’t showing signs of an issue. You don’t need to do it too often, but once a week is a reasonable interval when there’s no signs of infection present.

If you suspect an early infection with perhaps some mild debris, a little scratching or head shaking, it’s safe in most cases to start with some daily cleaning to see if you can get ahead of it.

What to Use

It’s important to use the right type of product. Using home-made solutions like vinegar, hydrogen peroxide, rubbing alcohol, and tap water, should be avoided. These solutions can be irritating to the sensitive ear canal. Water may just sit in the ear canal and make an early infection worse.

The best products to use contain either drying agents, like 2% salicylic acid, or an agent that breaks up ear wax and debris, like squalene. It’s also important to have a product that’s safe in situations where the eardrum may be affected or even ruptured. This can be more common in pups with chronic recurrent infections. Some products that are safe and effective to use include squalene products, trizEDTA products, and 1-2% acetic acid solutions.

When to Use

As mentioned before, ear infections can develop after swimming and baths. It’s important to clean the ears after water activities with an ear cleaner that has a drying agent to help evaporate the water sitting down in the ear.

When using an ear cleaner, squirt a generous amount down into the ear canal, massage the base of the ear until you hear a really satisfying squelching sound. This helps to break up debris stuck to the ear canal wall. Then allow your pup to shake his head, which further loosens debris. Finally, using a cotton ball or pad, wipe out the visible debris you can get to.

How to Use

I generally discourage the use of cotton swabs, like Q-tips, at home. Pushing a cotton swab too deep into the ear can cause more trauma and possibly rupture of the eardrum. If an infection is bad enough that a deeper cleaning is required, this should be performed by staff at your pup’s vet clinic.

Although ear cleaning can be uncomfortable and sometimes stressful for both you and your pup, try your best to make it a positive experience. Always make sure to use firm but calm words, take it slow, and provide treat rewards before, during, and after.

For Recurrently Red, Itchy Ears

Some pups out there with chronic allergy conditions may develop red, itchy ears, especially during certain seasons, or if they get into a certain food protein that results in a flare-up. A product I find to be very helpful with red, itchy ears but before a major infection breaks out, is Zymox.

Zymox contains a small amount of hydrocortisone as well as some enzymatic agents. This combination can help to stamp out and prevent that early flare-up of red, itchy ears before bacteria and yeast have an opportunity to readily overgrow.

spotted dog with big ears looks up

When to See Your Vet

Cleaning is generally okay with early signs of infection and mild debris. But if there’s any suspicion that an infection has been going on for awhile (i.e. several days to a couple weeks or more) or if the ear appears thickened, red, crusted, and especially if it’s painful, it’s too late for at-home care to make a significant difference.

Some folks might have an ear medication left over from a previous infection, and feel it may make sense to use that, especially if it might save them a trip to their pup’s doc.

It may be reasonable and safe in early cases to do this, in which case you should follow the directions exactly as detailed on the label from before. But the main thing vets worry about with self-medicating and treating at home, especially with chronic recurrent ear infections, is that the status of the eardrum is unknown unless we are able to visualize it during an exam.

Topical ear medications are designed for use only in the outer ear canal, with an intact eardrum. If the eardrum has become ruptured, as can happen with chronic infections, or infections of the middle ear, the middle and inner ear then become exposed to cleaning products and medications that can be toxic to these sensitive structures. This is why it’s generally always best to have your vet assess an ear infection and decide the best way to proceed.

What to Expect at the Vet

So, your pup has that red, crusty, smelly ear, and you’ve brought her to your vet. What happens next?

Getting a Good Look

The first thing your vet will do is a full physical exam, including a careful look at both ears. Using the otoscope, we’ll always endeavor a thorough look at the canal, which includes looking at the eardrum. However, if the ear is extremely painful or swollen, this may not be possible.

Collecting Ear Samples

The next thing we often do is collect swab samples from the ear canals and take a look at them under the microscope. This helps us see what type of growth is present in each ear and how much there is.

I do hear some pup parents dispute the need for these samples, called “cytologies”, since it’s “the same thing every time”. But this isn’t strictly true. I have seen the same dog have a bacterial infection, followed up with a yeast infection a couple months later. While there is only one species of yeast that we see, the type of bacteria present can also vary widely, which may make a difference in medication choice.

Quality Vs Quantity

The amount of growth I see can also make a difference with how I plan out a medication strategy at home, by helping me set expectations. An infection with a small amount of growth may clear up in 1-2 weeks, but a large amount may take 4 weeks or longer.

Cytologies are also important for knowing how successful a treatment course is, which is why it’s important to get new samples at each recheck visit. If bacterial presence is persistent after a couple weeks of diligent treatment, this can indicate that the bacteria is resistant to the antibiotic being used, which may then warrant changing medications or having a bacterial culture performed to figure out exactly what that species of bacteria is sensitive to.

If yeast is being really stubborn and is present after an initial treatment course, it’s not typically a resistance issue, but suggests the underlying cause, like an allergy, is not being well-addressed, or that more diligent home care is needed. This may necessitate a change in approach.

Continued Monitoring

Even if an ear looks visually normal after a course of treatment, it’s still important to collect that recheck sample, as microscopic levels of growth may still be present that need to be treated a little longer. If you stop treating too early based on visual improvement alone, you might see the infection come back full force in a couple more weeks.

Medication Plan

Based on how things look, including microscopic findings, your vet will then choose an ear medication and cleaner to use and a plan to follow. I typically prefer daily at-home medication use coupled with regular cleanings every couple of days. However, some dogs and their parents have a hard time with this. It may even affect their relationship, as ear cleaning and medicating can be frustrating and difficult for some. In this case, there are leave-in medications that many vet practices have available, which may last anywhere from one week up to 4 weeks.

Ear Cleaning

While discussing the medication plan with you, your vet will likely have your pup’s ears cleaned at the clinic. Veterinary staff are best trained to get cotton swabs deeper into the ear canal for a more thorough cleaning.

In some cases, where debris is seen really far down and cannot be removed with a simple cleaning, an ear cleaning and flush under sedation or general anesthesia may be recommended. This is not common, but may be necessary with severe or refractory cases.

Other Medications

It may be fair to expect discussions about other medications that may be needed in addition to topical ear medications.

Oral antibiotics don’t reach high concentrations in the outer ear, and so are often not employed with most infections we see. Less commonly, if an infection of the middle or inner ear is suspected, as is often the case if the eardrum is found to be ruptured, oral antibiotics will be used.

If the ear canal is severely swollen and stenotic, a short course of oral steroids is often used to help reduce the inflammation and open up the ear canal.

Antihistamines are sometimes employed, but unfortunately, while cheap and readily available, they’re not very effective for atopic dermatitis. Histamine just isn’t a big player, and only about ¼ of dogs may see an improvement with antihistamine use.

The End Stage Ear

Unfortunately for some pups, there may come a time when medical therapy for ears just isn’t an option anymore. This most often happens with chronic, recurrent infections where the ear canal has undergone so many changes like narrowing, thickening, and skin mineralization, that the very altered structure of the ear is now contributing to infection recurrence. The ear may be so thickened and stenotic that ear medication can’t even make it down there.

In these cases, surgical removal of the ear canal may be warranted. These pups otherwise may experience chronic pain that cannot otherwise be alleviated. The term for this procedure is called a total ear canal ablation (TECA) and is typically performed by a veterinary surgical specialist. Your veterinarian may bring this up if he or she feels that medical therapy is no longer possible. While it’s true this procedure will lead to removal of hearing in the affected ear, the truth is that a pup has likely already become deaf in that ear if it is that severely affected.

Long-Term Management and Prevention

As mentioned early on, ear infections always have an underlying cause. If water from swimming or bathing is to blame, prevention can be as simple as cleaning the ears afterwards with a good drying agent.

But if allergies are to blame, which is most often the case, more intensive management may be necessary than just treating the infections when they come up. Recurrent infections every couple of months can lead to chronic changes in the ear.

Inflamatory Therapies

Some pups can be managed with therapies directed at blocking the inflammatory response in the skin to allergens that leads to itchy, red skin and ears, and secondary infections. Oclacitinib is an oral medication that targets one part of this pathway, and an injection called Canine Atopic Dermatitis Therapeutic (CADI) targets another part. These are nice options as they target just the skin and not the rest of the body, are generally well-tolerated, and work quickly, often within 24-48 hours.

Allergy Testing

Environmental allergy testing is available sometimes through your own vet, or otherwise with a veterinary dermatologist. If the environmental allergens responsible can be determined, small amounts of these allergens can be combined into either an injectable or oral therapy aimed at desensitizing the immune system and lessening the response. This approach can work well, but the immune response can take a few months to reach max effectiveness.

Diet Trials

Food allergens can also be responsible, typically in the form of proteins. Meat proteins are the most commonly implicated, like chicken or beef. A strict diet trial is really the best way to determine if a food allergy is related. This constitutes a strict diet, usually with a prescription food, for 6-8 weeks. If signs of skin and ear problems lessen, what’s called a “challenge” can then be performed, where an old protein type is reintroduced. If this causes a flare-up, the offending protein has then been determined. Food trials require patience and persistence, as any deviation from the strict diet will necessitate starting over again.

If your pup has common recurrence and complications, your vet may recommend seeing a dermatology specialist. He or she can help really get to the bottom of recurrent ear infections, especially if secondary to allergies, with special testing and therapies.

Final Thoughts

Sometimes ear infections can be a one and done. And most of the time, each individual ear infection can be cleared up with the right combination of diligent care at home and prompt treatment by your veterinarian when flare-ups occur.

But figuring out and managing the underlying condition causing recurrent infections can be the most challenging. Hopefully, this guide has been helpful in understanding some of those causes and management strategies.

Chronic issues with ears can lead to a big rift in the bond pet parents share with their furry friends. But having a good understanding of what to expect and what is necessary to properly manage underlying conditions can make management more feasible. That’s where having a close relationship with your vet, and sometimes, a veterinary dermatologist as well, can make a big difference.


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