Dog Ear Infections: What You Need To Know

Ear infections are a common ailment among dogs, especially those with hanging or floppy ears, like Cocker Spaniels and Basset Hounds. In fact, a 2021 research study from the Royal Veterinary College found that one in every 14 dogs in the United Kingdom suffers from an ear infection every year.

Although dog ear infections can be uncomfortable, itchy, and even painful, they can typically be resolved with proper treatment from a veterinarian. Let’s discuss the common signs of ear infections in dogs, what causes them, and how to prevent them.

Types of dog ear infections

Your dog’s ear anatomy is made up of five components: The ear flap (also known as the external pinna), the external or outer ear canal, the eardrum, the middle ear canal, and the inner ear canal. An ear infection means that one of these parts of your dog’s ear is inflamed.

There are three types of dog ear infections:

• Otitis externa (outer ear infection) This is the most common type of ear infection in dogs. Otitis externa occurs when the cells that line the outer ear canal become inflamed.
• Otitis media (middle ear infection) This ear infection occurs when structures of the middle ear become inflamed, often as a result of spread from an outer ear infection.
• Otitis interna (inner ear infection) This is the most severe type of ear infection in dogs. Like a middle ear infection, this ailment typically develops when the infection spreads from other parts of the ear. If not treated properly, an inner ear infection can cause hearing loss and balance issues.

Symptoms of an ear infection in dogs

An ear infection can be uncomfortable and even painful for your pup. Here are some of the most common signs that your dog has an ear infection:

• Head shaking and itching. Head shaking and scratching at the ear are both indicators that your dog’s ear canal is itchy and/or painful.
• Odor. You may smell a strong, unpleasant odor from your dog’s head and ear area. 
• Red and inflamed ears. Your dog’s ear canal and surrounding tissue may be red or swollen. You may also notice that their ears feel warmer than normal.
• Discharge. Often there is a discharge from your dog’s ear when they have an infection. The discharge can range from a crusty or scab-like black substance to a yellow pustular discharge. 
• Neurologic deficits. In chronic or severe cases, dogs may develop neurological diseases that involve a head tilt or loss of balance.

Causes of dog ear infections

Common causes of ear infections in dogs include bacteria, yeast, and ear mites. Infection can also be caused by foreign objects, polyps, or tumors of the ear.

According to the Merck Veterinary Manual, however, dogs may actually be predisposed to ear infections due to the shape of their ear canals. Unlike humans, who have a short ear canal, dogs have a long narrow ear canal with an almost 90-degree bend as it travels to the deeper parts of the ear.

Your dog may also develop an ear infection as the result of:

• Genetics. Some dog breeds, such as Cocker Spaniels and Miniature Poodles, are genetically predisposed to develop ear infections. According to the American Veterinary Medical Association, these breeds have a greater density of apocrine glands, among other biological differences, that make them more prone to ear infections. Additionally, it’s been suggested that long, floppy ears – or excessive amounts of hair in the ear – tend to hold in moisture or heat, leading to the perfect setting for an ear infection.
• Moisture. Warmth and moisture in the ear can create just the right environment for yeast or bacteria to flourish. It’s not uncommon to diagnose a dog with an ear infection after they swim or receive a bath. After these types of activities, it’s important to clean your dog’s ears with an ear cleaner that contains a drying agent to prevent an ear infection.
• Interaction with other pets. Although not as common in dogs, ear mites (an infectious agent) can be transmitted to other pets by contact. Most often, ear infections due to ear mites are seen amongst puppies and cats.  
• Allergies. Both environmental and food allergies can predispose dogs to ear infections.
• Hypothyroidism. Low thyroid (T4) function may predispose dogs to chronic ear infections. 

How are dog ear infections diagnosed?

If your pup is experiencing any clinical signs of an ear infection, it’s important to have them evaluated by your veterinarian. Since ear infections can be caused by different infectious agents (bacteria, yeast, mites) or even a foreign body or tumor, it’s imperative to narrow down the underlying cause of infection quickly.  

Your veterinarian will typically run the following diagnostics:

• Performing a thorough physical examination
• Evaluate the ear with an otoscope
• Perform ear cytology (aka taking a sample of discharge from the ear canal and assessing the specimen under the microscope)

In more chronic or severe cases, your veterinarian may:

• Recommend a culture to ensure your dog receives the proper treatment
• Order full blood work (CBC and chemistry panel) to rule out an underlying condition, such as hypothyroidism

Luckily, once diagnosed properly, most dog ear infections will resolve with proper treatment and care.

How are dog ear infections treated?

Based on your veterinarian’s examination and diagnostic tests, they will prescribe the proper course of treatment for your pup’s ear infection. In general, treatment usually involves thorough flushing and cleaning of the ear with a medicated cleanser, followed by medicated ear drops applied daily for a specific period of time. Depending upon the type of ear infection and severity, your veterinarian may also prescribe a systemic antibiotic or steroid (i.e. anti-inflammatory medication).

• If a foreign body was found, it will be removed.
• If your dog was diagnosed with a mite, yeast, or bacterial infection, your veterinarian will prescribe a specific treatment for those agents.

Some dogs suffer with chronic ear infections secondary to allergies or low thyroid (hypothyroidism). Therefore, it’s particularly important for your veterinarian to properly diagnose and treat your pet’s ear infection. Diagnosing an underlying condition is crucial to treating and preventing ear infections in dogs.

How can dog ear infections be prevented?

Here are a few steps you can take to prevent ear infections in your dog:

• Regular ear cleaning. Properly cleaning your dog’s ears once per week with a medicated ear cleaning solution may help to prevent infections. You should always ask your veterinarian what the best ear medication is for your pooch.
• Dry ears after water activities. Following a bath or swim, make sure to clean your pup’s ears out with a drying agent. Again, ask your veterinarian which ear cleaner is best for your dog.
• Treat any underlying diseases. If your dog suffers from allergies or hypothyroidism, it’s important to properly treat these conditions to prevent secondary ear infections.

The bottom line on dog ear infections

Dog ear infections may be common, but you have all the knowledge you need to keep your pup as safe and healthy as possible. Work with your veterinarian to learn the best way to clean your dog’s ears and always bring them in for a visit if you think you see signs of an infection.