Causes of Dog Ear Infections

The causes of dog ear infections are many and varied. While an ear infection may appear to come from out of nowhere, there is generally an underlying cause, though it may not be an obvious one.

Because ear infections are common dog health problems, your dog will likely fall victim to one sooner or later.

Part of the reason for this lies in the anatomy of a dog's ear which makes it attractive to parasites, fungus, bacteria, as well as the collection of plant debris while out on walks. And once any of these life forms take up residence, they can raise havoc and drive your dog crazy!

No doubt, as a caring pet parent, you will want to help your dog avoid these pesky and painful ear problems as much as possible.

Learning about what can cause a dog ear infection will put you in the best position to do this. Plus you'll be sparing him from a lot of serious discomfort and the necessity to visit that "scary" place known as the vet's office!

So let's get to it.

golden retriever headshot

Common Causes of Dog Ear Infections

One of the main causes of ear infection in dogs is something an owner can remedy immediately:

  • Wet ears!

While the inside of a dog's ear already has a certain natural level of yeast and bacteria, excessive moisture remaining after bathing or swimming can change this balance, allowing bacteria to build up and trigger an infection.

Yeast and bacteria love and thrive in a moist environment - particularly when it is also warm and dark.

Not only is it a good idea to clean and dry your dog's ears thoroughly after they are exposed to water, but also to look for foreign object that may have entered the ear during a swim.

Foreign objects remaining in the ear can lead to the development of an ear infection.

Other Causes Of Dog Ear Infections

  • Excessive wax can not only be an indicator of an ear infection, but also the cause of one. Wax build up can occur if the ears are not kept clean, leading to an increase in microbial activity. This in turn can alter the ideal amount of wax present for its normal protective function.

  • Invaders of the ear such as fox tails, grass seeds and any other type of plant matter. When foreign matter of this type gains entrance to the ear and is not removed promptly, it can become embedded into the fragile skin of the ear causing irritation, inflammation and you guessed it - ear infection. 
  • Dog owners themselves can contribute to the onset of an ear infection in dogs if they get into the habit of using cotton-tipped swabs during grooming. Even with the best of intentions, they can accidentally damage the delicate anatomy of the ear, or push materials including wax to a deeper level thereby cutting off air circulation or causing irritation.

On a side note, when it comes to air circulation in a dog's ear, you may hear some people indiscriminately recommend plucking out hair inside the ear to improve circulation. One reason dogs have hair in their ear is to protect it from substances that might invade the ear canal.

Another thing to keep in mind is that after hair is plucked out, a serum is excreted which turns out to be irresistible to bacteria.

In my view, hair should only be removed for a medical reason and upon the advice of a vet. A hair mat blocking the ear canal and causing secondary problems might be a valid reason for removal, but consulting with a professional is always a good decision when it comes to dog ear problems.

ear wash for dog

More Common Causes

  • Ear mites. These microscopic insects are quite often the instigator of ear infection in dogs, or more accurately said, they put in motion the mechanism that gets the ball rolling.
  • When mites invade the ear canal they obtain food by piercing the pet's skin which subsequently triggers an allergic reaction. The result of this is characterized by the pet experiencing an intense amount of itching which naturally leads to an intense amount of scratching. By and by, the ear becomes highly irritated and inflamed, setting the stage for an infection.
  • Allergies. Sensitivities to food and/or medications, are frequent causes of ear infections in dogs because they can set up conditions in which bacteria can thrive. In fact, antibiotic ear preparations, used excessively can lead to a situation where they have no effect on the bacteria.

    When it comes to food sensitivities, it may take awhile to identify the actual ingredient, but while this is going on vets often recommend strengthening the immune system to make it more efficient in identifying real threats as opposed to harmless ones. In fact, ear infections in themselves are quite often a sign that the immune system is in a weakened condition.
  • Lastly, a word about hormone imbalances and in particular - hypothyroidism, a disease associated with a slowing of the metabolism. When a dog has this type of thyroid deficiency, it may show up in a variety of signs. One of the more visible ones is an adverse change in coat condition including cause hair loss. Another is a predisposition toward ear infections.


So there you have it, now you know some of the main causes of ear infection in dogs. I hope you put this information together with regular ear inspection and cleaning to keep your dog's ears as healthy as they can be.

If you have made it to the bottom of this page, you are a blessing to your dog - as he is to you.

Related Dog Health Pages

  1. Common Dog Diseases
  2. Ear Infection
  3. Ear Infection Causes
Share this page:
Solo Build It!