8 Common Causes of Ear Infections in Dogs (and Cats) and How to Treat Them
It seems like dog owners are always talking about ear infections. This makes sense—the shape of a dog’s ear canals make it such a prevalent issue that the American Kennel Club (AKC) estimated that up to 20% of dogs have some form of ear disease! Ear infections are notoriously frustrating for pets and pet owners alike. Our goal is to help you navigate ear complications in your dogs and cats by teaching you how to detect and understand the signs of ear infections, when to seek help for treatment, and ways to prevent them.
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Why Are Dogs and Cats Susceptible To Ear Infections?
Despite having similar ear canal structures, dogs are far more likely to be afflicted with infections than cats. The ear opening travels down as a long thin tube and creates an "L" shape as it turns almost 90 degrees to end at the eardrum. This shape naturally causes a collection of wax, debris, and moisture, all of which can be predisposing factors to an infection. Normal, healthy ears should be able to self-clean the small amounts of wax they naturally produce, but complications and external factors can impede this system.
Underlying Causes and The Importance of Routine Checks
Ear infections are often a symptom of another disease or condition, making it all the more important to be aware of any sudden incongruencies in your pets’ ears. This is one of the main issues with ear infections: although they may seem like a minor discomfort at first, they can escalate quickly and cause permanent damage if left untreated. When an untreated infection spreads from the outer portion of the ear to the middle or internal ear canal, the severity increases; some issues that could result from these types of infections include:
In cases where the condition has persisted too long to completely resolve the infection, surgery may be required. Recurrent or chronic ear infections can exacerbate the damage every time they come back, so it’s essential to address the underlying conditions causing the infections to affect a long-term cure. Catching things early on and addressing them holistically is the key to preventing recurring ear problems.
Signs of Your Pet May Have An Ear Infection
Using our ear health checklist from 7 Ways To Assess Your Pets Health At Home, signs of a healthy ear should look like the following:
Ear Health Checklist
No bad smell
No scratches or sores
No excessive wax build up
No redness or inflammation
No excessive head shaking or holding ears abnormally
If you are seeing any changes from the above, it should warrant a visit to your vet.
Common Causes of Ear Infections in Dogs & Cats
1. Hairy Ears
Many breeds like poodles, poodle crosses, schnauzers, and other long or curly-haired breeds can have hair that overflows deep into the canal. This can become problematic as it prevents the routine removal of wax and traps moisture—two factors that can significantly increase the chances of infection. The trapped wax and moisture means that the normal, small amounts of yeast and bacteria in the ear can multiply, resulting in irritation, inflammation, and eventually, infection.
2. Narrow Ears
This is a concern particularly for breeds with excess skin, like the Shar-Pei, or in pets with previous trauma or infections that have led to scarring or thickened skin in the ear canal. The narrowed canal exacerbates the trapping of waxy debris and moisture—again, causing naturally occurring yeast and bacteria to grow beyond normal levels, and infection ensues. In extreme cases of chronic infections, the ear canal can even become calcified—meaning it turns into bone! This situation is rare but irreversible and often requires radical surgery to treat; just another reason to get ahead of these issues before they can escalate!
3. Wet Ears
While water and swimming can undoubtedly contribute to ear concerns, they are often overemphasized as a cause. Sure, swimming and soaked ear canals can lead to infections, especially in less-than-clean water, and yet plenty of pets swim regularly and don't experience recurrent ear infections—and some that do! Generally, avid swimmer pets prone to ear infections also have one of the other predisposing factors of ear infections: excess hair, narrow ear canals, excess wax, or allergies—it might be the extra moisture is just pushing them over the edge!
That being said, if you can't keep your pet out of the water, they may require a little more of your attention to keep their ears healthy compared to non-swimming pets—even if they don't seem prone to ear infections. Remember, prevention is the best medicine.
4. Pendulous Ears
While this is often implicated in breeds with long ear flaps covering their ear canals, like Cocker Spaniels, Basset Hounds, and even Scottish Fold cats, this is often just a contributing factor, not a direct cause. Pendulous ears tend to trap moisture and prevent wax from being cleared out naturally, especially if they sit tight to the ear canal, almost creating a seal. It is even more important to regularly check these types of pets' ears so you can recognize when something is amiss and deal with it immediately. It’s a hard life, playing with floppy ears when checking for infections...but someone has to do it.
5. Waxy Ears
Waxy ears can occur due to genetic predispositions or from health or hormone-affecting conditions. The excess wax creates irritation, which can lead to inflammation—and then your pet is just a step away from infection. Pets with these conditions require regular ear cleaning to maintain healthy ear wax levels.
6. Ear mites
More commonly found in cats—but occasionally in dogs as well—ear mites are microscopic parasites that make their home in the external ear canals of our pets. The symptoms are relatively identifiable: the mites leave a waxy brown/black debris that looks like dark sand or coffee grounds; they’re incredibly itchy and irritating to your pet, so be on the lookout for head shaking, itching, and inflammation in the ears.
Fortunately, ear mites are easily treatable in 1-2 vet visits, and they don't tend to come back—unless your pet is encountering a source outside the home (e.g. interacting with barn cats) or if they weren't thoroughly cleaned out the first time.
7. Foreign bodies
We often see this in pets that like to run through the woods, tall grass, or stick their heads into places they shouldn't necessarily be. Seeds, grass awns, foxtails, and a wide assortment of other flora can migrate into the ear canal and cause serious pain, inflammation and infections. Again, in a worse case scenario, these foreign objects can rupture eardrums and cause permanent deafness if left untreated. It never hurts to give your dog a full once-over when they come back from a serious romp outside!
8. Compromised Immunity and Hormone Imbalances
This one can be tricky to put together at first, especially if you’re not yet aware of any other chronic conditions your pet may have. Any condition that suppresses the immune system raises the likelihood of infections, and ears are not the exception to this rule. Pets with immunocompromising diseases that affect the endocrine system and create hormone imbalances, such as Cushing's Disease or Hypothyroidism, often experience ear infections. This is because their immune system is not functioning as it should to prevent infections in general. Don’t panic: there are ways to mitigate this through a natural, healthy diet and regular probiotic and prebiotic supplements.
Learn more improving your pet’s gut health!
9. Recent Vaccination
We occasionally see ear infections pop up in puppies or kittens that have been recently vaccinated. It’s often thought of as a juvenile ailment, and while it can be easily treated and resolved if it does happen to your young pet, you need to make a note of it and let your vet know. Ear infections are often a result of stress on the immune system—which is a normal reaction to a vaccination—but if this happens, your puppy or kitten should not receive any more vaccinations while this infection is present. Vaccinations should only be administered to healthy pets. If an infection of any kind is in play, their immune system is already working hard to deal with that—why tax it more by administering a vaccine? If this happens with an adult pet, the same information applies: diagnostics should be looked into even more closely, as an adult with a mature immune system should be able to tolerate vaccinations.
If your vaccine schedule is now out of whack, consider getting a vaccine titer done while the ear infection is being treated. (Titer testing occurs before vaccinations to check antibody levels—it's not a bad idea to avoid unnecessary vaccinations whenever possible.)
10. Allergic Skin Reactions and Atopy
This is by far the most common underlying condition causing ear infections—which is not surprising, considering allergies are associated with alterations in the immune system! Both cats and dogs can have this condition; it is often accompanied by general itching and irritation of the skin, possibly excessive licking of the feet/limbs or other areas, and hotspots or localized areas of skin infections.
You might be tempted to treat an allergy directly, either with medications or hypoallergenic diets, but be careful of “band-aid solutions”. When we talk about allergies, it can be described with some variance: some can be true allergic conditions, in which the body is reacting to substances in their environment and/or food. On the other hand, it could be a symptom of a severe issue with their gastrointestinal tract. A digestive system that is doing poorly, such as in "leaky gut" situations, can mimic the signs of true allergies in animals. Tending to gut health holistically can lead to significant improvements in these conditions.
View our blog on allergies for more information: Food Allergies in Pets
However, if your pet has a true allergy or is atopic, then chronic ear infections are often part of this condition. Again, treating the underlying condition will usually resolve the issue, or at the very least, bring about a notable improvement in the recurrence of ear infections. Starting with a healthy and biologically appropriate diet can help strengthen your pet's immune system and improve their conditions, including allergies and atopy.
Here’s an easy illustration of what general ear infections mean...