Ear Infections (Otitis) in Dogs

Otitis Externa: The Most Common Type of Ear Infection in Dogs

This article is focusing on otitis externa, meaning ear infections in the ear canals and not the middle or inner ear (the parts behind the eardrum). Dogs have a very long ear canal compared to people. The ear canal dives down, then moves inward toward the skull, giving it an “L” or “J” shape. This means there is more surface area for wax to accumulate, moisture to get trapped, and infection to develop. There can even be foreign material trapped deep in the ear canal, like plant material or insects!

Moisture and excess wax give the normal yeast and bacteria in the ear material to feed on and overproduce, leading to inflammation, pain, odor, and discharge. Ear mites also infect the ear canals and burrow into the skin, causing bleeding and pain.

Ear infections are listed as among the 6 most common health problems in dogs. The ears of a healthy dog do not have an abnormal buildup of ear wax and/or debris. A small population of bacteria and yeast are normal inhabitants of the outer ear canal. When something upsets the condition of the ear canals, the microbial population overgrows and causes an infection.

A dog’s ear canal is divided into the outer/external ear, middle ear, and inner ear. There are 3 types of ear infections in dogs; they are classified based on the location.

• Otitis externa - inflammation of the outer ear canal
• Otitis media - inflammation of the middle ear canal
• Otitis interna - inflammation of the inner ear

Among the 3 types of ear infections in dogs, otitis externa is the most common because it occurs in the part of the ear that is most exposed to the environment.

Inflammation causes the infected ears to become painful, reddish, and develop an offensive odor. There may be a black or yellowish discharge from the ears. These changes usually result in increased cerumen (wax) production along the external ear canal, which contributes to an increase in local humidity and pH of the external ear canal, thus predisposing the ear to secondary infection. In severe cases, a dog may tilt his head towards the infected ear. This can indicate a more serious infection that may have affected the nervous system. Hearing loss or balance issues are often seen in otitis media or interna.

Ear infections can be quick in onset (acute) or chronic and recurrent. They can occur in one or both ears.

Chronic ear infections are characterized by the formation of crusts or thickening of the ear canals. This can cause the narrowing of the ear passages. If anti-inflammatory medications fail to address the swelling of the ear tissues, your vet may recommend surgery, the most common of which is “lateral ear resection”.

Are certain breeds prone to ear infections?

Some dog breeds are more prone to developing ear infections. These dogs tend to possess certain characteristics, such as the shape of their ears or ear conformation. Genetics has also been shown to be an important predisposing factor in some dogs.

Long, Floppy Ears

Dog breeds with ears that are long and floppy commonly get chronic ear infections. These dogs may also have a higher number of glands that produce earwax (ceruminous glands) compared to other breeds. Cocker Spaniels, Beagles, Basset Hounds, and Setters are just some of the breeds that possess these characteristics.

Small Ear Canals

Bulldogs, Chow Chows, and the Chinese Shar-Pei are just some of the canine breeds with narrow ear canals. This anatomical feature predisposes them to ear inflammation and infection.

Dog Breeds Prone to Allergies

While allergies can affect any breed of dog, Labrador Retrievers, Golden Retrievers, Boston Terriers, and Shih Tzus are just some of the dog breeds that tend to be more prone to allergies and sensitivities that can pave the way for chronic or recurrent ear infection.

Breeds with Excess Hair in the Ear Canals

Some dogs like the Bichon Frise, Shih Tzu, and Poodle have excess hair in their ear canals which can create a favorable environment for yeast and bacteria to thrive. Excess hair can prevent proper airflow that keeps the ear canal dry, as well as trap dirt, debris, and excess ear wax.

Causes of Ear Infections in Dogs

There is a long list of causes of ear infections in dogs. In many cases, an underlying problem compromises the normal protective barrier of the ears. Moisture in the ears also creates a favorable environment for bacteria and yeast to multiply and cause infection.

Some of the most common causes of ear infections in dogs include:

• Excessive moisture in the ear passages from bathing or swimming
• Foreign bodies, such as foxtails or grass awns, that get into the dog’s ear
• Ear mites
• Allergic reactions to allergens in pet food or the environment
• Abnormal growths in the ear canal (polyps)
• Hormonal issues such as hypothyroidism
• Certain types of cancer
• Autoimmune diseases such as lupus or pemphigus
• Injury to the ear such as an aural hematoma
• Excessive or incorrect ear cleaning

Symptoms of Ear Infection (Otitis Externa) in Dogs

• Shaking the head
• Scratching the ears
• Rubbing ears on the ground or other surfaces
• Holding one or both ears lower than usual
• Redness to the ear canal entrance
• Yellow, brown, black, or pus-like discharge in the ear canals
• Pain when the ear is touched

How to Tell if Your Dog Has an Ear Infection

If your pet is showing symptoms of an ear infection, they need to see their vet as soon as possible. The vet will take a sample of the discharge to evaluate under the microscope to look for ear mites, yeast, bacteria, and inflammatory cells. Your vet will also use an otoscope to look deep into the ear canal to be sure the eardrum is still intact and appears healthy. They can also look for any foreign material that may be present.

If there is too much wax and infected material in the ear, your dog may need to have the ears flushed and cleaned out at the vet clinic. This may require sedation as the ears can be very painful due to the infection and inflammation.

What to Expect at the Vet When Your Dog Has an Ear Infection

At the veterinary clinic, your pet will undergo a complete physical exam. A thorough history will also be taken by your vet. Be prepared to answer important questions that may include the following:

• How long the symptoms have been occurring
• If your dog has frequent allergies
• If your dog has been diagnosed with certain medical conditions
• If your dog has a history of ear infection
• Medications that your dog may be taking
• Your dog’s diet
• How often do you clean your dog’s ears and what products are you using
• If you pluck or trim your dog’s ears and how often
• Recent activities that your dog has engaged in such as swimming, grooming, baths, etc.

A special instrument known as an otoscope is used to examine the inner parts of the ear canal. Depending on the findings of your vet, there may be a need for additional tests or procedures to be performed to arrive at an accurate diagnosis. These may include the following:

• Getting samples from inside the ear for microscopic exam and for culture to identify which pathogens are present - yeast, bacteria, etc.
• Blood tests can help rule out medical conditions, such as endocrine disorders, autoimmune diseases, and other underlying issues.
• In severe or chronic cases, biopsies or x-rays may be indicated.

Are dog ear infections contagious?

The majority of ear infections in dogs are not contagious. However, it depends on the cause. If parasites, like ear mites, are the underlying cause, they can be extremely contagious. If you have several dogs in your home and one has been infested with ear mites, all of your pets are assumed to be infected and will need to be treated at the same time.

A bacterial ear infection can also be contagious. This is especially true with methicillin-resistant Staphylococcus aureus (MRSA). But cases in dogs are rare.

Will my dog’s ear infection get better on its own?

Most cases of ear infections in dogs won’t go away on their own. Any type of ear problem should be brought to the attention of your vet. There’s a need to evaluate the infection and integrity of the eardrum. Treating a ruptured eardrum can be quite complicated and will need professional attention. Some ear cleaning products and medications can also be toxic to a dog’s middle ear.

Chronic ear infections will require time (about 6-8 weeks) and the appropriate treatment regimen to clear up. Even if the symptoms appear to ease off after a week or two of medications, it is very important to follow the length of treatment time recommended by your vet. Stopping the medication too soon or if the underlying cause is not identified, may cause the ear infection to recur and this can significantly affect your dog’s quality of life. It could also lead to total loss of hearing. Antibiotic resistance can also be an issue if the proper dosage and treatment duration are not followed.

How to Treat Dog Ear Infections

Ear Cleaning

Your vet will clean your dog’s ears to clear the ear canal of ear wax, debris, and discharge that may be present. This is necessary so any medication that is administered to the dog’s ears can reach the inner ear passages.

Medications

A medicated ear cleaning solution is usually used by veterinarians to clean the dog’s ears. Your vet may prescribe an appropriate ear cleanser that you can apply to your dog’s ears at home. Topical medications, oral antibiotics, and anti-inflammatory medications may also be prescribed. Not all dogs tolerate ear medications at home, so discuss long-acting ointments that your vet can instill at the clinic that can stay in the ear for weeks.

Total Ear Canal Ablation (TECA)

This is a surgical procedure that involves removing the ear canal with the diseased tissue to prevent the recurrence of ear infections. TECA surgery is a treatment option for severe ear infections and those that have become chronic problems and in which other treatments have failed.

Treating ear infections is not a one-time deal. Any lapses in treatment can increase the risk of recurrence. You should follow the advice of your vet concerning the following:

Recheck appointments - Your dog needs to be checked regularly to monitor his response to the medication and see if healing and repair are proceeding as they should. Sometimes, there is a need to change or add medication to address specific issues.

Medications - The importance of letting your dog finish the full course of the prescribed medication cannot be overemphasized. Even if the symptoms have disappeared and your dog seems to be getting better, you need to follow through to ensure that the infection does not recur. Resistant infections can also be a problem when the full course of treatment is not finished. Ear infections that recur or do not resolve with treatment may have an underlying allergy component or have a resistant strain of bacteria present. Your vet will discuss the next steps, often submitting a sample of the discharge for culture and sensitivity testing to ID the exact bacteria types that are present and determine which antibiotic is the next best option. Dogs with allergic otitis will have intermittent flare-ups and need to be on a consistent home ear cleaning routine and perhaps allergy medications and special diets to reduce the frequency of flare-ups.

Additional Information

There is a risk of deafness with dog ear medications. Certain antibiotics and steroids are more commonly implicated. This risk is higher if the eardrum is torn or ruptured. If you notice your dog is not hearing as well during treatment for an ear infection, let your vet know immediately. They will likely recommend stopping the medication and coming in to get the ear canal flushed out thoroughly with sterile saline to remove as much medication as possible. Luckily, this is often a temporary deafness and the hearing comes back in a few weeks to months.

Expert Tips to Prevent Ear Infections in Dogs

Once the main causes of ear infections in dogs are clear, we can talk about preventive measures. Below are the most popular recommendations among veterinarians:

1. Proper hygiene: clean your dog's ears carefully and with suitable products.

Ear hygiene is vital to prevent ear infections in dogs. Frequency and technique are important. The best way to clean your dog’s ears is to lift the ear, spray or flush the ear canal with an approved solution, and then massage the base for 20 to 30 seconds. After that, your dog will shake its head to remove the fluid and debris.

Although swabs can be used in the folds inside the ear, it’s best to avoid inserting them into the ear canal. As in humans, this can push wax inside, cause plugging, and have the opposite effect.

It’s also important to use suitable solutions. Homemade ones, such as dilute hydrogen peroxide, vinegar, and rubbing alcohol, are discouraged because of their abrasiveness and high-water content. Therefore, it’s best to consult with a vet for the most effective and safest option.

2. Keep your dog's ears dry.

In addition to the special washing of the ears, keeping them dry is a priority. One option is to place cotton balls inside them to prevent moisture from getting inside during bathing.

But experts on the subject say that the best way to prevent ear infections in dogs is to clean and dry them every 5 to 10 days. The frequency will change if yours is a swimming breed; in that case, drying should be done immediately to avoid the colonization of bacteria and yeast.

3. Avoid removing hair from the ear canals unless necessary.

Excessive hair can always cause problems, but before proceeding to eliminate the hair in your dog’s ears, certain criteria must be applied. Removing hair from the ear canals is not recommended in dogs that have never had infections in the past. Also, this should always be done in the hands of an experienced groomer or veterinary professional.

4. Use appropriate supplements for healthy skin and hair.

Although no supplements can form the basis of a pet's diet, they are useful when allergies predispose them to ear infections. For these cases, experts recommend a daily supplement of Omega-3 fatty acids that will help reduce inflammation and strengthen their immune system. Be sure to discuss recommended brands and dosing with your veterinarian.

Read more:

10 Facts About Your Dog’s Ears

Pinnal Vasculitis: Why are my dog’s ears crusty?

Examining and Caring for Your Pet’s Ears

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