Ear Infections in Dogs: Why They Keep Coming Back

In brief

There are five things you should know about ear infections. First: they are among the most common diagnoses there are—in UK primary-care data, an ear infection was recorded in 7.3 percent of all dogs within a single year. Second, and this is the key sentence: A recurring ear infection is usually the result of an underlying cause. It is a finding, not a diagnosis. Third: the most common trigger behind it is an allergy—if all you do is give drops, you are treating the result every time. Fourth: before anything goes into the ear, it has to be clear whether the eardrum is intact—otherwise some active ingredients can damage hearing. Fifth: cotton swabs, oil, vinegar and home remedies have no place in the ear canal.

Few problems run in an endless loop as often as the inflamed dog ear: the drops work, a few weeks later it is back, and by the fourth time nobody believes in a solution anymore. This article explains why that happens—and what needs to change for it to stop.

Note: This article is general information and does not replace a veterinary examination. Ear drops from a previous treatment should never be reused without the ear being checked again.

👉 Prevention and health at a glance: Dog Health Basics

1. Why the dog’s ear is so vulnerable

A dog’s ear canal is built differently from ours, and that difference explains a large part of the vulnerability. What it does not explain is why an infection develops in the first place—that takes a trigger, and that is what this article turns to from section 3 onward.

The canal does not run straight but is L-shaped: first a longer vertical section going down, then a bend and a horizontal section leading to the eardrum. This protects the inner parts well from injury—and at the same time it means that whatever gets in has a hard time getting out again. Discharge, moisture and dirt collect at the bend.

Then there is the environment: dark, warm and moist. For the yeasts and bacteria that live there in small numbers anyway, these are ideal conditions as soon as something shifts.

And the ear canal is lined with skin. Whatever itches and becomes inflamed on the belly does the same in the ear—just under considerably worse conditions. That is exactly where the connection this article is about comes from.

Two things follow from this for everything else. First: everything you can see from the outside is the smaller part—the decisive section lies beyond the bend and cannot be assessed without an otoscope. Second: because the ear canal is lined with skin, a recurring ear infection belongs in the same workup as an itchy belly or licked paws—not in a category of its own.

2. How to recognize it

The early signs are unspectacular; the late ones are impossible to miss.

• Head shaking and scratching at the ear
• Head tilt, often toward the affected side
• Odor from the ear—sweetish, yeasty or foul
• Discharge: brown, greasy, yellowish or purulent
• Redness and swelling in the ear canal, a thickened ear flap
• Sensitivity to touch, turning away when touched, growling
• Rubbing the head on furniture or the floor

Two points are often overlooked. Ear infections hurt—often more than owners assume, because the ear canal has no room to give. A dog who suddenly pulls away when stroked on the head may not have a behavior problem at all. And a hematoma of the ear flap—a tightly swollen, doughy ear flap—is usually the result of violent head shaking, which makes it a sign of an ear problem, not the actual finding.

👉 Why pain in dogs is easy to miss: Recognizing Pain in Dogs

2.1 The signs that come too early to be noticed

The list above describes an ear in which something is already going on. With a dog who has recurring episodes, though, it pays to look much earlier—because the earlier a flare-up is spotted, the shorter and milder it can be.

A single head shake that is new. Not the obvious, repeated shaking, but the one when getting up that wasn’t there before.

Light scratching that becomes a habit. Many owners only register the vigorous scratching—the transition before it often takes days.

A changed head position when listening. Some dogs hold their head slightly tilted before anything else is noticeable.

Odor before discharge is visible. This is often one of the most reliable early signs. If you briefly sniff the ear of a dog with a known history once a week, you will notice a change before it can be seen.

Warmth and redness on the inside of the ear flap, even without discharge.

This adds up to a routine that takes twenty seconds a week: lift the ear flap, look inside, sniff, briefly touch the inner surface. For a dog who has been through several episodes, this is one of the most effective measures you have at home—it won’t prevent a flare-up, but it can shorten it considerably.

3. Recurring ear infections have a cause behind them

This is the core of the article, and the professional literature states it clearly: Recurring ear infections in dogs are usually the result of an underlying cause. They rarely arise on their own; they develop because something else has changed the conditions in the ear canal.

In chronically recurring ear infections, atopic dermatitis—environmental allergy—is among the most common underlying causes. This is the established view in veterinary dermatology and does not rest on a single study.

A recent study does, however, provide direct evidence of this connection: in a six-month, blinded and controlled trial in atopic dogs, the rate of ear infection episodes fell on a therapeutic diet (Watson et al., 2026). This does not show that diet in general is the cause of ear infections—it shows that in dogs with already known atopic dermatitis, a measure aimed at the underlying disease measurably relieves the ears. That is precisely the point of this section. And here lies the reason for the endless loop: drops fight the yeasts and bacteria that have multiplied. And they do work—the dog is often symptom-free after ten days. What they don’t do is treat the allergy that triggered the inflammation in the first place. As soon as the drops run out, the same conditions carry on, and the next flare-up often follows.

That leads to the most important practical rule: From the second or third ear infection on, the right question is no longer “which drops?” but “why again?” Anyone who hasn’t started looking for the cause after the third time will often still be giving drops the tenth time.

In some dogs, the ear is even the first and, for a long time, only sign of an allergy—months or years before anyone thinks of the skin or the paws.

👉 Getting to the root of it: Itching in Dogs

4. The four-factor model

In dermatology, an ear infection is not treated as one single thing but broken down into four groups. That sounds academic, but it is the way of thinking most likely to get you out of the loop.

Primary causes start the inflammation. They include allergies, ear mites, foreign bodies such as grass awns, hormonal disorders and, less often, tumors or autoimmune diseases. Without treatment at this level, the infection usually comes back.

Secondary factors are what you see and smell: yeasts and bacteria that multiply in the altered environment. They account for most of the acute symptoms and usually respond well to treatment—but they are not the reason.

Predisposing factors make an ear more vulnerable without causing disease themselves: floppy ears, narrow or very hairy ear canals, a lot of swimming, a humid climate, frequent incorrect cleaning.

Perpetuating factors keep things going once they have become chronic: permanent thickening and narrowing of the ear canal, calcification, a damaged eardrum and involvement of the middle ear.

The last point explains the most stubborn cases. If the middle ear is involved, a reservoir can sit there that topical drops barely reach—and from there the outer ear can be recolonized again and again.

5. Which dogs are particularly affected

An analysis of 22,333 dogs from UK primary-care practices found a recorded one-year frequency of 7.30 percent. The two characteristics with the strongest association were breed and ear shape (O'Neill et al. 2021).

Sixteen breed types were clearly above crossbreeds. At the top was the Basset Hound, with roughly six-fold higher odds (odds ratio 5.87), followed by the Shar Pei, the Labradoodle, the Beagle and the Golden Retriever.

The Labradoodle’s place on this list is noteworthy, because doodle crosses are often sold with the promise of better health. When it comes to ears, that promise doesn’t hold—the combination of floppy ears and dense hair growing into the ear canal tends to be unfavorable.

Other contributing features: pendulous ears that cover the ear canal and reduce ventilation; narrow ear canals; and frequent contact with water.

Important for context: ear shape and breed are predisposing factors, not primary ones. A Basset doesn’t get an ear infection because he has floppy ears—he gets one more easily when something else comes along.

👉 Why breeding traits have health consequences: How to Recognize a Responsible Breeder

5.1 What follows from the breed list—and what doesn’t

Breed lists get misread in both directions, so here is how to put them in context.

They are not a prognosis. A Basset Hound with roughly six-fold higher odds is not six times as certain to get an ear infection—compared with a crossbreed, his odds are higher, and most Bassets in the analysis had no ear infection that year.

Nor are they an all-clear. A dog with erect ears who isn’t on the list can still develop an allergy—and then his ears will itch too. The most common primary cause doesn’t care about ear shape.

What actually follows is attentiveness. For a dog with floppy ears or a narrow or very hairy ear canal, the weekly routine from section 2.1 is worthwhile before anything has happened for the first time—not because he will get sick, but because it takes less to tip him over.

And when choosing a dog: if you decide on one of these breeds, you are deciding on an ear that needs more attention. That is no reason to rule the breed out, but it belongs in the calculation—just like grooming for a long-haired dog.

6. Ear mites: the special case in young dogs

One primary cause deserves a mention of its own, because it behaves differently from everything else in this article: ear mites.

They are highly contagious, mainly affect puppies and young dogs as well as animals from group housing and international rescue—and they are rather rare in adult single dogs from a stable home. Typical is a crumbly, dark brown, almost black discharge reminiscent of coffee grounds, along with intense itching.

Two things make them a special case. First, unlike allergy, they are a cause that can actually be eliminated—here treatment leads to a cure, not just to control. Second, all animals in the household have to be treated as well, including cats and including those that show no signs. Otherwise the mites move back.

They are detected in an ear swab under the microscope. That is exactly why examination comes before treatment: in a young dog with dark discharge, mites are a likely suspect—but yeasts look similar from the outside, and the treatment is completely different.

7. What happens at the vet

A proper workup involves three steps, and the second is the one most often left out.

Otoscopy. The ear canal is examined all the way to the eardrum. The vet assesses redness, swelling, narrowing, the type of discharge, foreign bodies—and whether the eardrum is visible at all and intact. With severe pain or a badly narrowed ear canal, this is only possible after pretreatment or under sedation.

Cytology. A swab is smeared onto a slide, stained and looked at under the microscope. Only then does it become clear whether yeasts or bacteria predominate—and with bacteria, whether they are cocci or rods. The choice of medication depends on this. Without cytology, an essential basis for targeted treatment is missing—brown gunk looks similar with yeasts and with bacteria. With a clear-cut first episode, a microscope check isn’t always done right away; but with a recurring ear or one that isn’t responding, it should be part of the workup at the latest.

Cytology has a limit, though: it shows the shape of the bacteria, not the species and not their susceptibility. Rod-shaped bacteria in particular are often associated with the problematic, constantly recurring cases and are frequently resistant to several active ingredients. If they are found, or if an ear doesn’t respond as expected, a bacterial culture with susceptibility testing should therefore be added—a lab culture that determines which drug will actually work. Without this step, it is easy to reach reflexively for a broad-spectrum product the germ may long since have become resistant to, and the course can drag on for months.

Looking for the cause, at the latest when the problem recurs: allergy workup, ruling out ear mites, checking the thyroid, searching for foreign bodies.

In stubborn or chronic cases affecting both ears, an ear flush under general anesthesia and imaging are added to assess the middle ear.

👉 What anesthesia means for this: Anesthesia in Dogs

8. Why the eardrum decides everything

This point is the most important safety issue of the whole topic, and it is the reason old drops must not be reused.

If the eardrum is damaged, active ingredients get into the middle ear. Some substances that are unproblematic in the outer ear canal can damage the balance or hearing organ there. The result can be permanent hearing loss or a lasting balance disorder.

That is why the rule is: before any treatment, the eardrum is checked to see whether it is intact—and that is why a leftover bottle from last year is not a good idea. What was right last time may be wrong this time, because the findings have changed.

The same applies to ear flushes: what belongs in an ear canal with an intact eardrum does not belong in one with a hole.

In practice this regularly meets with incomprehension, which is why the explanation is worth giving: in a badly inflamed ear, the eardrum often can’t be seen at all on the first day. The ear canal is swollen shut and full of discharge, and the dog is in pain. In that case the ear is first cleaned gently or pretreated with anti-inflammatories for a few days so the swelling goes down—and only then can the vet assess what lies behind it. If your veterinarian says she can’t see the eardrum yet, that isn’t a failure; it’s the right order of steps.

8.1 When the middle ear is involved

The four-factor model names middle ear involvement as one of the things that keep chronic cases going. Because it is overlooked so often, here it is in more detail.

Behind the eardrum lies the tympanic cavity. If the eardrum has ever been ruptured—even if it has since healed—material may have accumulated there. Topically applied drops usually don’t reach this space. From there, the outer ear canal can be recolonized again and again, and each round of treatment then often works only briefly and fails.

This is suspicious above all in an ear that doesn’t heal for good despite appropriate treatment, in one-sided chronic cases, and in dogs that have already been through several rounds.

Signs that go beyond the ear should be taken particularly seriously: a persistent head tilt, loss of balance, flickering eyes, a drooping lip or an eyelid that doesn’t close on one side, a changed pupil. They suggest that nerves in the vicinity are involved and should be checked promptly—not at the next routine appointment.

Middle ear involvement isn’t determined with the otoscope alone, but through an ear flush under anesthesia and imaging. That is exactly why this is the step many owners put off—and exactly why some cases drag on for years.

9. Treatment: what actually works

Treatment runs on two levels at the same time, and both are necessary.

Acutely, the ear is cleaned and treated with a product that matches the cytology findings—a different one for yeasts than for bacteria. Often it contains an anti-inflammatory component, because the swelling itself narrows the ear canal. It is important to finish the treatment completely, even if the dog is lively again after three days—stopping early is one of the main reasons for quick relapses.

At the root, whatever triggered the inflammation is treated. Without this part, acute treatment is merely a postponement.

With very painful or badly narrowed ears, the dog is often pretreated with anti-inflammatories for a few days first, so that the ear can be examined and cleaned at all.

When an ear canal has been chronically remodeled, narrowed and calcified over years, at some point no treatment reaches it anymore. What remains then is surgery. That sounds drastic, but for these dogs it is often the moment when years of constant pain come to an end.

9.1 When nothing gets through anymore: the surgical route

The last paragraph of the previous section mentions surgery in a single sentence. Because this decision is hard and often made too late, it deserves to be spelled out.

What is meant is complete removal of the ear canal, along with opening of the tympanic cavity. The ear canal is not repaired but removed—because there is nothing left to save. That sounds radical, and for these dogs it is often the point at which years of constant pain end.

Two things address the most common concerns. On hearing: an ear canal that has been narrowed, thickened and calcified for years hardly conducts sound anyway. In these dogs, hearing loss has usually set in long before surgery—the operation rarely takes away anything that was still there. On quality of life: what goes away is a permanently inflamed, painful organ.

What honesty requires adding: the procedure is demanding, it is performed at specialized facilities, and complications are possible—among other reasons because important nerves lie right next to the surgical site. The prospects are better when it doesn’t come at the end of a years-long odyssey.

The most important practical sentence on this topic is therefore: asking about surgery is not an admission of failure—with a chronically remodeled ear, it is a question you should actively raise, before the dog gets two more years of drops.

10. What “looking for the cause” actually means

This article says in several places that from the second or third ear infection on, the cause has to be investigated. What that means in practice usually remains unclear—and that is exactly why it often doesn’t happen. Here is how it works.

10.1 The groundwork you do

Before anything is examined, the history is the most valuable material—and it lies with you.

How often, since when, which ear. A simple list with the date of every episode so far. One-sided or both-sided is one of the most telling single pieces of information: one-sided cases point more toward a foreign body, a tumor or a local cause; cases in both ears point more toward a systemic one such as allergy.

The pattern over the year. If flare-ups occur in spring and summer, that points more toward a seasonal environmental allergy. Year-round flare-ups don’t rule out an environmental allergy—to house dust mites, for example—but they also fit a food allergy or a predisposing factor.

What else is going on. Paw licking, red armpits, anal gland problems, head rubbing—these things are often reported separately even though they belong together.

What has been given so far. Names of the products, duration, effect. “It helped for a little while” is different from “it did nothing at all,” and each leads to different conclusions.

10.2 The steps at the vet

The order follows the four-factor model from section 4, from the bottom up.

First, the current flare-up is brought under control and the ear is calmed down enough to be assessed. At the same time, cytology is done and, where needed, culture with susceptibility testing.

Then the vet looks for the simple primary causes: ear mites via swab, foreign bodies via otoscopy, the thyroid via a blood test. These are the causes that can be treated relatively directly.

Then comes the allergy workup, and this is the part that takes months—ruling out parasites, an elimination diet with a challenge, a clinical diagnosis of atopic dermatitis. How that works is covered in a separate article.

And in chronic cases, the middle ear is assessed, via an ear flush under anesthesia and imaging. This is the step that explains the most stubborn cases—and the one that gets put off the longest, because it means anesthesia.

10.3 Why the effort pays off

Next to “just get more drops,” this route looks like a lot of work, and it is. The trade-off, though, looks different than you might think.

Four to six rounds of treatment a year over several years often add up to more than a structured workup—in money, in appointments and, above all, in pain for the dog. And they can end in the state section 9 describes: an ear canal so remodeled that no treatment reaches it anymore.

The point at which the workup pays off most clearly is therefore not the fifth flare-up but the second.

11. Ear cleaning: right and wrong

Cleaning makes sense—regularly for some dogs, never for others. A healthy, odorless, clean ear doesn’t need care. Cleaning too often can disrupt the ear’s environment.

What matters is the choice of product, and it is not a matter of taste. Cleaners differ in their composition, and the right choice depends on the microscopic findings—yeasts call for a different environment than bacteria. Over-the-counter care products with plant extracts, fragrances or oils are usually unproblematic on a healthy ear, but they sting considerably on inflamed or scratched skin and can shift the environment further. With a diseased ear, the cleaner therefore belongs in the prescription, not in the shopping cart.

How to do it: put a generous amount of the prescribed ear cleaner into the ear canal, massage the base of the ear from the outside for about twenty to thirty seconds, let the dog shake, and then wipe only the visible ear flap with a cloth or cotton pad. The cleaning happens through the liquid and the shaking, not through wiping.

How not to:

• No cotton swabs in the ear canal. Because of the L-shaped canal, they tend to push material further in instead of getting it out, and they can injure the eardrum.
• No oil, no vinegar, no alcohol, no hydrogen peroxide. Oil stays put and can become a breeding ground, vinegar and alcohol irritate inflamed skin, and with a damaged eardrum all of these are dangerous.
• No cleaning of an acutely painful ear before someone has looked inside.
• No leftover bottle from a previous treatment.

Opinions differ on hair in the ear canal. Routinely plucking it from healthy ears is now considered more harmful than helpful, because it irritates the skin and creates entry points. With heavily overgrown ear canals, targeted trimming can make sense—that is a case-by-case decision, not a rule.

👉 Why home remedies don’t belong in the ear: Human Medications and Dogs

12. The sudden one-off: foreign bodies

One picture doesn’t fit the pattern and matters because it plays out differently: a dog who during or right after a walk suddenly shakes his head violently, scratches at one ear and is clearly in pain usually doesn’t have a creeping infection but something in his ear.

The classic culprit is a grass awn. Its barbs only allow one direction—it can migrate deeper, down to the eardrum and beyond. This is not a case for watching and waiting or for flushing, but for a prompt examination; removal is often done under sedation.

👉 What grass awns can do in summer: Grass Awns in Dogs

The typical picture is so characteristic that it is almost a diagnosis in itself: one-sided, sudden, intense—a dog who was unremarkable until the walk and afterward shakes his head, is sensitive to touch on one side and rubs his ear on the ground. Where this picture shows up, a foreign body is the first suspicion, not the last, and the season adds to it.

To put this in context with the rest of the article: this is the case in which waiting does the most obvious harm. Most of the rest here can wait for an appointment the next business day—the exception being the signs from section 8.1 that go beyond the ear. A foreign body, on the other hand, can keep working its way in as long as it is in there—and the closer it gets to the eardrum, the more involved its removal becomes and the more likely it is to require anesthesia.

13. Why the ear is also a training topic

This part falls within a trainer’s remit, and it often decides whether a treatment is carried through at all.

An infected ear hurts. If drops go into it twice a day, the dog can come to associate having his head touched with pain—often quickly. After ten days of treatment, some dogs have learned that hands on the head mean nothing good, and that can last beyond the infection.

This creates a cycle that is common in practice: the dog resists, treating him becomes unpleasant, it gets done less often or incompletely—and incomplete treatment, as section 9 explains, is one of the main reasons for quick relapses.

What helps during treatment. Something good right after you start handling and during the application, not as a lure beforehand—the order determines what the situation becomes associated with: if the handling announces the good thing, the situation can gradually become more pleasant; if the treat always comes first, it can itself become the herald of the unpleasant drops. Keep it short; don’t restrain. If there are two of you, one gives the drops while the other feeds. And bring up pain relief explicitly: an ear that hurts so much that every touch triggers a defensive reaction needs pain management as well, not just restraint.

What helps outside of treatment. Practice handling the ears when nothing hurts—lift the ear flap, take a quick look inside, treat, done. For a dog with recurring ear infections, this is not a gimmick but preparation for the next flare-up, which is statistically likely.

And the point that saves the most: a dog who willingly lets you examine his ears may need sedation for otoscopy less often at the vet—and for these dogs, sedation is needed more often over time than anyone would like anyway.

👉 Desensitization and Counterconditioning in Dogs

14. What you can do at home

Look inside once a week and take a quick sniff. Ten seconds per ear. That way, changes are often noticed before the dog suffers.

Dry the ears after swimming and bathing—let the dog shake and pat the ear flap dry.

Keep a log of flare-ups. Date, which ear, season. After three entries you can often already see a pattern that is worth more in the exam room than any description.

Keep count of how often it comes back—and actively bring up looking for the cause when it’s the third time.

Finish treatments, even if things look better.

Train ear handling while the ears are healthy. A dog who has learned to accept ear checks is more likely to let you treat him even when it hurts—and that often decides whether treatment at home works at all.

15. Limits of the evidence

The frequency figures come from recorded practice diagnoses, not from population screening. An older analysis by the same research group arrived at a higher figure of 10.2 percent than the 7.3 percent from 2016—different years, samples and case definitions may explain this. Both figures show the same order of magnitude; neither is the exact value.

The four-factor model is an established clinical framework, not an experimentally tested causal structure. It organizes clinical practice well, but the boundaries between the groups are fluid in the individual case.

And the statement that recurring ear infections are usually secondary is a core professional conviction in dermatology, based on clinical experience and case series. It is well founded—but it is not the result of a randomized trial.

On the structure of the evidence: the frequency and risk figures come from an analysis of UK primary-care practices—that is, from documented reasons for veterinary visits, not from a study of all dogs. Whatever wasn’t brought to a vet doesn’t show up, so mild cases tend to be underestimated. The statements on the four-factor model and on how a workup proceeds come from the veterinary dermatology literature and describe the established view, not the result of a single study.

16. Conclusion

Ear infections are common, painful and, in most stubborn cases, misunderstood: they are a finding, not a diagnosis. If you are still asking which drops will help after the second or third round, you are asking the wrong question—recurring ear infections are usually the result of an underlying cause, and allergy ranks high among them. What makes the practical difference is a look under the microscope instead of at the color of the gunk, an intact eardrum before anything goes into the ear, and the willingness, from the third time on, to look for the why instead of the next bottle.

👉 What matters when choosing: Choosing a Good Veterinarian

If you take away only one thing: keep count. How often, since when, which ear, what time of year. At the second flare-up, this list is the most valuable piece of information in the exam room—and it is the one reason anyone switches from “which drops?” to “why again?”

Key takeaways on ear infections in dogs

A recurring ear infection is a finding, not a diagnosis. It is usually the result of an underlying cause—most often an allergy. If all you do is give drops, you are treating the result every time.

From the second or third episode on, the question is no longer “which drops?” but “why again?” The point at which a workup pays off most clearly is the second flare-up—not the fifth.

Anatomy explains the vulnerability, not the cause. The L-shaped ear canal drains discharge and moisture poorly, and the environment is dark, warm and moist—but that doesn’t mean it has to become inflamed.

Ear shape and breed are predisposing, not causal. In UK practice data, the one-year frequency was 7.30 percent, with the Basset Hound at roughly six-fold higher odds (O’Neill et al., 2021). A Basset doesn’t get an ear infection because he has floppy ears—he gets one more easily when something else comes along.

Without cytology, an essential basis for targeted treatment is missing. Brown gunk looks similar with yeasts and with bacteria, but the treatment is different. With rod-shaped bacteria or a lack of response, a culture with susceptibility testing should be added.

Before any treatment, the eardrum is checked. If it is damaged, some active ingredients can permanently damage hearing and balance—which is why a leftover bottle from last year is not a good idea.

If the eardrum can’t be seen on the first day, that is the right order of steps and not an oversight: the swelling has to go down first.

Cotton swabs, oil, vinegar and alcohol have no place in the ear canal. Cleaning happens through liquid and shaking, not through wiping—and a healthy, odorless ear needs no care at all.

Ear mites are the special case. They mainly affect young dogs and animals from group housing, can actually be eliminated, unlike an allergy—and all animals in the household have to be treated as well, including cats.

References

• O'Neill, D. G., Volk, A. V., Soares, T., Church, D. B., Brodbelt, D. C. & Pegram, C. (2021): Frequency and predisposing factors for canine otitis externa in the UK – a primary veterinary care epidemiological view. Canine Medicine and Genetics 8: 7. https://doi.org/10.1186/s40575-021-00106-1 (22,333 dogs from a population of 905,554; recorded one-year frequency 7.30%; breed and ear shape as the characteristics most strongly associated with otitis; elevated odds in, among others, the Basset Hound 5.87, Shar Pei 3.44, Labradoodle 2.95, Beagle 2.54 and Golden Retriever; secondary and perpetuating factors as drivers of chronic cases)
• Watson, N. et al. (2026): Incidence Rate of Otitis Externa Episodes in Atopic Dogs Is Reduced by a Therapeutic Diet in a 6-Month Randomised, Blinded, Controlled, Clinical Trial. Veterinary Dermatology. https://doi.org/10.1111/vde.70017 (six-month randomized, blinded and controlled trial in atopic dogs: lower rate of ear infection episodes on a therapeutic diet. Cited here only for this finding—the general view of recurring ear infections as the result of an underlying cause rests on the established state of veterinary dermatology, not on this study)
• O'Neill, D. G., Church, D. B., McGreevy, P. D., Thomson, P. C. & Brodbelt, D. C. (2014): Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England. PLOS ONE. https://doi.org/10.1371/journal.pone.0090501 (ear infection, at 10.2%, as the most common recorded diagnosis in this older analysis)
• Olivry, T., DeBoer, D. J., Favrot, C., Jackson, H. A., Mueller, R. S., Nuttall, T. & Prélaud, P. (2015): Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA). BMC Veterinary Research 11: 210. https://doi.org/10.1186/s12917-015-0514-6

Frequently asked questions about ear infections in dogs

The questions asked most often in the exam room