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Ear Infections In Dogs: Types, Causes, Symptoms, And Treatment

Ivana Crnec
Written by: Dr. Ivana Crnec
What are the symptoms of an ear infection in dogs? Read on to discover how serious ear infections are and how you can protect your dog.

It is estimated that around 20 percent of dogs have some type of ear problem, and in most cases, the problem is caused or complicated by an ear infection.

Compared to humans, dogs are at higher risk of developing ear infections because of the ear anatomy and the ear canal’s shape.

Namely, the dog’s ear is designed to protect itself from external insults and injuries. Therefore, the dog’s ear canal is more vertical and somewhat L-shaped.

When wax, debris, or any type of foreign material enters the canal, gravity encourages the accumulation to go deeper.

Once the accumulation is deep inside the canal, the dog can’t get rid of it by vigorous head shaking.

Ear Infection – Terms And Types

The scientific name for an ear infection is otitis. Based on the location within the ear, where the infection develops, there are three different forms of ear infections:

  • Otitis externa – the most common and usually benign form of infection. The infection affects only the cells located on the ear canal’s external portion.
  • Otitis media – occurs of the infection spreads from the external to the middle portion of the canal.
  • Otitis interna – in extreme cases, the infection may spread and affect the entire ear canal.

Otitis externa is relatively benign, but if left untreated, it progresses and develops into otitis media or internal.

Otitis media and interna are serious health issues that may have long-term consequences, including deafness, balance impairment, and facial paralysis.

Dogs with otitis media and interna may have intact or ruptured eardrums. The state of the eardrum is an important prognostic factor.

Ear Infections – Causes, Symptoms, And Treatment

Bacteria, Fungi, And Yeast

A combination of bacteria and yeast or fungi is the most common cause of infection of the ear’s external portion.

It should be noted that dogs cannot catch this type of infection from another dog. These infections occur when the microorganisms that are already present in the ear canal start multiplying excessively.

They are called opportunistic microorganisms. Their excessive multiplication results from condition change, for example, increased moisture inside the ear canal or the presence of wax or other discharge that serves as a good food source.

Over time the number of opportunistic microorganisms increases so significantly that they stay displacing the beneficial microorganisms.

The number one opportunistic microorganism responsible for otitis externa is the yeast Malassezia.

This yeast takes advantage of all types of ear canal inflammations – from allergies to ear mites. The second, the most common opportunistic microorganism responsible for causing chronic otitis is the bacterium Pseudomonas.

Usually, the two opportunistic microorganisms work together. In addition to shaking their heads, affected dogs scratch their ears and regions around the ears.

The inside of the ear becomes hot, painful, and foul-smelling with a waxy discharge. If the infection affects only one year, the dog will probably hold its head bent in the direction of the affected ear.

In dogs with erected ears, the affected ear can be kept lower than the healthy ear.

The type of discharge gives a lot of information about the culprit. For example, soft and dark brown discharge is usually associated with Malassezia infections.

Pseudomonas infections result in yellowish, moist, and fruity-smelling discharge with a paste-like consistency.

Since the two infections occur concurrently, the vet will prescribe a solution containing an antibiotic, antifungal, and anti-inflammatory agent. In more severe cases, the vet will prescribe oral treatment as well.

Ear Mites

Ear mites (scientifically known as Otodectescyanotis) are pesky parasitic insects that feed on wax and skin debris. They cause an ear infection called otodectic mange.

The otodectic mange is particularly common among puppies. More precisely, it is estimated that 10% of ear infection cases in puppies are due to ear mites.

The ear mites live mainly inside the ears but are prone to leaving the ear canal and spending some time around the ear openings. They are hard to eliminate and often cause re-infestations.

Suppose your puppy is shaking its head vigorously, scratching its ears excessively, and has an unpleasant smelling, mahogany-black ear wax. In that case, it is safe to assume the underlying problem is ear mites.

The ear mites pinhead-sized, white dots that move frenetically when exposed to light. For example, if you swab your puppy’s ear and place the swab against a dark background, you will be able to see them wriggle around the wax.

Ear mites are extremely contagious, which means if your puppy has them and you live in multiple-pet households, chances are all of your pets will have them. However, there is comfort in the fact that they cannot be transmitted to humans.

The vet will clean the ears and prescribe a pyrethrin-based ear solution.

The solution should be applied for around three weeks because the medication is efficient only against adult mites and not eggs. Therefore, the treatment is used until all eggs have hatched and all adult mites are destroyed.

To kill the ear mites traveling outside the ear canal, the vet will recommend applying a topical anti-flea treatment that works against mites.

More often than not, ear mite infections are complicated by opportunist yeast and bacteria. In such cases, the vet will prescribe an antibiotic or antifungal.

Foreign Bodies

The most common foreign body found in dogs’ ear canals is plant material – grass seeds, foxtails, grass blades, barley awns. These foreign particles can easily find their way inside the ear canal, especially if they get attached to the ear openings’ hair.

Once they enter the ear canal, there is no going back. Foxtails are perhaps the most dangerous because of their structure and inability to get back, which means they can only progress deeper into the canal.

Plant material is common, but it is not the only foreign body concern in dogs. According to reports, the list of foreign bodies removed from dogs’ ears includes pebbles, small wood sticks, and ornamental buttons.

A dog with a foreign body in its ear canal will shake its head vigorously in an attempt to get rid of the troubling item.

Based on the type of foreign body and the infection’s advancement, there can be a bloody or nasty smelling discharge with variable coloration.

The vet will remove the foreign body with alligator forceps and an otoscope. Ear infections are quite painful, which is why, based on the case, the vet may decide to sedate the dog before removing the foreign body.

If necessary, the vet may prescribe antibiotics, anti-inflammatories, and pain killers.

If you suspect your dog has a foxtail inside its ear, to prevent the seed from puncturing the eardrum, you can instill around ten drops of baby mineral oil inside the ear. This will delay the onset of the complications and give you time to arrange a vet visit.

Allergies

Allergies and ear infections are closely related. Based on reports, 80% of dogs with food sensitivities eventually develop ear infections. In dogs with allergic skin issues, the incidence of ear infections is a bit lower – they appear in 50% of the cases.

A dog with an ear infection caused by skin and food-related allergy will have red and extremely itchy ears, but there will not be any discharge.

In such cases, treating the ear infection requires managing the underlying allergic condition.

Ear Ticks

There is an extremely rare ear tick (Otobiusmegnini) that attaches and lives inside the ear canal. The tick causes severe yet local infection accompanied by a foul-smelling and bloody discharge.

The treatment is straightforward – removing the tick with alligator forceps and the aid of an otoscope, solves the problem. A vet should perform the removal.

Maintaining A Good Ear Hygiene

Keeping your dog’s ear clean is the best way to prevent tedious and painful ear infections. Here are some critical tips on how to keep your dog’s ears clean and healthy.

Practice Regular Checkups

The most basic approach is to examine your dog’s ear frequently. This does not mean you need to become an ear wax police patrol and look inside your dog’s ears every day.

The rule of the thumb is to practice checks once per week. You can only observe the external portions of the ear and the beginning of the canal.

If there is anything suspicious, like debris, wax, too much hair, or a weird smell, contact your veterinarian.

Ignoring the signs of trouble is a mistake. The sooner you have your dog examined by a vet, the sooner the vet will initiate treatment and the better the outcome of the treatment.

If left untreated, even a small issue may progress and cause significant ear damage.
The vet will examine the ears with an otoscope – a device designed specifically for ear examination.

Cleaning Your Dog’s Ear

If you checked your dog’s ear and they are clean and odor-free, leave them alone.

In dogs without chronic ear infections, routine cleaning is not necessary. However, if your dog has a history of ear infections, you can use an ear cleaning solution designed specifically for dogs.

If there is a bit of wax accumulated, remove it with a cloth or cotton ball moistened in mineral oil. You can use another moistened cloth or cotton ball to wipe the accessible portions of the ear.

If there is too much wax, instill a few minerals or baby oil drops inside the ear and wait for several hours. Once the wax softens, it will be easier to have it removed.

Alternatively, instead of mineral baby oil, you can use a wax eliminating solution. It is advisable to rinse the solution with distilled lukewarm water.

Once you are done with the moist part of the cleaning, gently press a cotton ball or dry cloth inside the ear to absorb the moist.

When cleaning the ears, the most important thing is not to go too deep. If you go too deep inside the ear canal, you risk pushing the debris further or even rupturing the eardrum.

Ear swabs designed for humans are definitely forbidden for dogs. The dogs’ ears have different anatomy and are more prone to damages.

It should also be noted that alcohol-based solutions must not be applied inside a dog’s ears since they are very harsh and often cause severe skin irritations.

Finally, if there are too many hairs inside the ear canal, pluck them with your fingers or tweezers.

The plucking is not painful, but it can be a bit uncomfortable, so you may need an assistant to help you with this task. If, instead of plucking, your dog is more comfortable with trimming, go for it. The goal is to keep the canal hair-free.

Removing the hair is important because if it overgrows, it will block the canal and prevent it from breathing, which increases the risk of infections. A hair-free canal has better air circulation and a lower risk of developing infections.

Keeping The Ears Dry

The organisms responsible for ear infections thrive in moist conditions. Therefore, it is vital to keep your dog’s ear dry and prevent the infection-causing microorganisms from multiplying.

This includes drying the ears after routine cleanings and preventing water from entering the ears during baths.

You can put cotton balls inside the ears before bathing your dog. Just do not forget to remove them after the bathing session is over.

Examine The Ears After Walks

Be diligent about checking your dog’s ears after playing in tall grasses. Look for grass seeds and other plant material, as well as for ticks.

Barley awns and foxtails can get caught in the hair around the ear, and if they enter the ear canal, they travel only further down, which will eventually cause infection.

Ticks pose a more severe problem and may cause systemic disease.

From an ear-health point of view, the blood leakage they cause may trickle down the canal, and since blood is a good food source for many microorganisms, infections are likely to occur.

That is why it is advisable to keep the hair around the ear openings well-trimmed. If there is no hair to catch onto, the seeds and ticks will not be able to enter the ear and work their way through the ear canal.

Droopy Ears Require Extra Attention

Once upon a time, dogs had uniformly shaped and sized ears. Today, dogs come with a variety of differently shaped and sized ears.

Some shapes and sizes are easier to take off, while others are high-maintenance. Each ear shape has its own maintenance requirements.

For example, in dogs with hairy, big, and floppy ears, like Cocker Spaniels, it is advisable to tape the ears back for a few hours, especially when it is hot and humid. These taping sessions can be practiced few times per week.