Dog Ear Infections: Symptoms, Causes, and Treatment

Key points

• Dog ear infections can cause scratching, head shaking, and an unusual discharge from the ears.

• Diagnosis is made by a veterinarian examining inside the ears and performing lab tests. 

• Treatment involves cleaning the ear and ear drops for simple cases, with more extensive treatment needed in advanced or severe cases.

• Prognosis (outcome) is good in most cases, and partly depends on prompt treatment.

• If left untreated, ear infections can spread deeper in the ear canal and can cause loss of hearing.

Common in

• Dogs with long, floppy ears or particularly hairy ear canals, such as spaniels, basset hounds, and poodles
• Dogs prone to skin allergies, such as West Highland white terriers 
• Ear infections can happen in any breed

Symptoms & types

There are different types of ear infections in dogs, depending on the location of the infection within the ear. ‘Otitis’ is the medical term for inflammation (redness and swelling) of the ear. So, ear infections are grouped into the following types:

• Otitis externa:  inflammation in the outer ear canal, which leads from the pinna (ear flap) to the eardrum.
• Otitis media: inflammation of the middle ear, meaning the eardrum and the structures just on the other side of it.
• Otitis interna: inflammation of the inner ear, which includes the organs for hearing and balance.

Otitis externa is the most common type of ear infection seen in dogs. Sometimes symptoms come on very suddenly (acute infection) and are very obvious. Other times they come on more gradually and are harder to spot. When ear infections go on for a long time, they are known as ‘chronic’ infections. The infection may affect just one or both ears. Sadly, ear infections often recur, unless the underlying cause is also treated.

When there is an ear infection, your dog may shake their head, scratch their ears, or rub their face along the ground.

The exact symptoms will vary depending on the severity and type of infection, but common signs that your dog has an ear infection include:

• Shaking their head
• Scratching their ears, or rubbing their head on the ground
• An unusual black or yellow discharge from their ears, which may be smelly
• Red, hot, scabby, or crusty skin inside the pinna (ear flap) or around the entrance to the ear canal
• Becoming head shy, or yelping when you touch their ears
• Tilting their head to one side

If you notice any of these symptoms, it’s important that you take your dog to a vet as soon as possible. Ear infections are painful and the longer they go on, the harder they are to treat. If left untreated, ear infections can spread deeper in the ear canal and permanently damage your dog’s hearing. In fact, studies have shown that half of all chronic infections in the ear canal (otitis externa) will lead to infections deeper in the ear (otitis media). 

Understanding the diagnostics

Your veterinarian will examine your dog’s ears with an otoscope, an instrument that allows them to see into your dog’s ear canals. They will be looking for masses, foreign bodies (such as a grass awn), and assessing if the eardrum is damaged. 

Your veterinarian may take a swab from the ear canal and examine the material collected under a microscope. They can then determine whether the infection is caused by bacteria, yeast, or both. They may also wish to send the swab to a lab for culture and sensitivity. This tells them exactly which type of bacteria or yeast are present, and which treatments work best against them.

If your dog’s ears are very painful, they may be reluctant to have them examined. They may need sedation or general anesthetic for these tests to be carried out properly and safely.

If your dog has a chronic or recurring ear infection, then your veterinarian will want to investigate for an underlying cause. This could involve blood tests and imaging of the ear.

Ear infections are painful and the longer they go on, the harder they are to treat.

Learning About The Causes

Dog ears become infected when bacteria or yeast within the ear canal are able to multiply uncontrollably. Dogs have an ‘L’ shaped ear canal, which means there is poor airflow and ear wax gets easily trapped. Bacteria and yeast love this warm, moist environment!

There is usually an underlying cause for ear infections in dogs. Common underlying causes include:

• Ear mites
• Foreign bodies in the ear canal
• Tumors or growths in the ear
• Underlying health issues, such as an underactive thyroid
• Allergies

There are also some factors that will make some dogs more prone to getting ear infections, such as:

• Long, floppy pinnae (ear flaps)
• Narrow or hairy ear canals
• Frequent swimming
• Breed: Poodles, spaniels, and basset hounds are particularly prone

It’s important to note that any dog can suffer from an ear infection, so be sure to see your veterinarian if they are showing any of these signs.

Treatment should always be carried out under the instruction of your veterinarian.

Best Treatment Options

Treatment will start with cleaning the ears. In mild to moderate cases, this may be started by your veterinarian in the consult room. They will then teach you how to clean your dog’s ears at home, and you will be sent home with some cleaner. In more severe cases, your dog may need to have their ears flushed under a general anesthetic. Cleaning is essential for the treatment to work.

Antibiotic or antifungal treatments may be given topically, as drops placed in the ears, or by mouth. Sometimes a combination is needed. Anti-inflammatory treatment is usually required at the same time, for pain relief and to help open up the ear canal by reducing the swelling. This allows any topical treatment to penetrate better. Anti-inflammatories may be given in ear drops or by mouth.

It’s crucial that the underlying cause is treated, or the infection will either not resolve, or will recur. In severe chronic cases when medication is not working, then surgery on the ears may be required.

Conclusion

If you’ve ever had an earache, you will agree that it is very painful! Dogs are often stoic creatures who mask their pain well. Well, now you know how to spot an ear infection in your dog, and you know to call your veterinarian as soon as possible.