Allergic Ear Infections (Allergic Otitis) in Dogs

How do allergies cause ear infections in dogs?

Allergies cause the skin barrier to break down and increase the wax production in the ear canal. This allows the low number of normal yeast and bacteria on the skin and in the ear to overproduce and allow more severe strains of bacteria to thrive. This leads to increased inflammation, pain, and discharge from the ear.

Dogs with seasonal allergies tend to get ear infections around the same season each year. Dogs with food allergies or non-seasonal environmental allergies may have ear infections recurring throughout the year.

Since dogs with allergic otitis will have repeated ear infections, this chronic inflammation can cause the ear canal tissue to scar, become calcified, and reduce the opening of the ear canals. This makes treatment even harder as the medication has a hard time reaching the deeper ear canal regions.

Symptoms of Allergy-Induced Ear Infections

The symptoms for allergic otitis are the same as otitis externa but tend to recur during the allergy season or be more frequent year-round.

• Shaking the head
• Scratching at the ears
• Redness to the ear flap or entrance to the ear canal
• Discharge from the ear canal
• Pain when the ear is touched
• Thickening of the ear canal
• Rubbing the face/ear on the ground or furniture
• Licking the paws excessively (a general sign of an allergy)
• Itching or licking other parts of the body (a general sign of an allergy)
• In severe cases, if the eardrum ruptures, the infection can spread to the middle and inner ear causing symptoms like head tilt, walking abnormally, circling, falling over, or pain when eating or opening the mouth fully.

How does my vet know if my dog has an ear infection related to allergies?

A good physical exam and exam down into the ear canals is the first step. The next step is usually cytology, evaluation under the microscope, of the material in the ear to look for yeast and bacteria.

Based on these results, an initial ear medication can be started. Treatment is typically recommended to last for 2-3 weeks, then the ears must be rechecked to ensure the infection has fully resolved. If the infection is still present after the initial treatment course, your vet may recommend a Culture and Sensitivity test to submit to the lab. This way, the bacteria can be grown, identified, and certain antibiotics can be tested to see which one is the next best option for treatment. Not all bacteria respond to the same antibiotic and dogs with allergies that have been on and off ear medications multiple times have a higher risk of developing more severe bacterial infections with more resistance to available antibiotics.

Ear infections are painful and lead to a lot of discharge in the ears. Your vet may recommend sedating your dog to thoroughly clean out the ear and better assess the eardrum before starting treatment. Removing as much discharge as possible will help the medications work better and reduces inflammation and pain in the ear. It’s important that your vet can assess the eardrum. There are medications that are commonly used in ear treatments that can cause deafness and this risk is highest if the eardrum is torn, allowing the drugs to reach the middle or inner ear. If the eardrum is not healthy, your vet will likely recommend oral medications and very select topical treatments.

It’s critical that your dog comes back in for the recommended recheck exam, often 2-3 weeks after starting treatment. We need to be sure the infection has completely resolved. Dogs with allergic otitis can have harder to treat ear infections and more frequent ear infections due to the allergy trigger.

How can I prevent allergic otitis?

If your dog has allergic otitis as a result of a food allergy, your vet will discuss beginning a novel protein or hypoallergenic prescription diet. The diet needs to be fed for at least 2-3 months to assess the response and a few diets may need to be tried

If your dog has flea allergies that trigger allergic otitis, be sure all pets in the home are on consistent flea control, the home and yard are being treated for fleas, and the home is being vacuumed at least weekly to remove any fleas that may get inside. Oral flea products tend to be the most effective for flea allergic pets.

For dogs with environmental allergies (atopy), discuss allergy testing with your vet or referral to a veterinary dermatologist. Dogs can be given Antigen therapy to help reduce their immune system's overreaction to their allergies. There are also steroids, antihistamines, and newer anti-itch allergy medications like Apoquel and Cytopoint that can help reduce ear and skin issues in allergic dogs.

Regular ear cleaning and even a cleaning product to reduce wax can help reduce ear infections in allergic dogs. Discuss options with your vet, along with a tailored ear cleaning regime for your dog.

Read more:

Swelling of the Ear (Aural Hematoma) in Cats and Dogs

How to Perform a Food Trial for Your Pet’s Allergies

Common Myths About Allergies in Dogs

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