Ear Infections (Otitis Externa) in Dogs and Cats

By: Rebecca Donaldson, DVM

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Outer ear infection is one of the most common types of infections seen in pets and is referred to as otitis externa.

How can I tell if my pet has an ear infection?

An ear infection may occur in just one ear or can affect both ears at the same time. Most pets will exhibit signs of ear discomfort. They may shake their head or paw at their ears. The ears themselves often become red and inflamed, and you may notice a buildup of earwax with a foul odor.

What causes the infection?

Ear infections can be caused by many different things. Something as simple as bathing or swimming can leave behind water in the ear that is the perfect environment for bacteria or yeast to grow in. Other causes of infection include allergies, parasites, polyps, or endocrine disorders.

If your pet is experiencing ear infections frequently, it can be a sign of an underlying allergy. Allergies in pets can be caused by airborne pollens, dust, fleas, and food. Ear mites, a type of parasite, are a common cause of infections in cats (especially those that go outdoors), though cats can suffer from allergies and ear polyps as well.

Are some dogs more likely than others to develop an ear infection than others?

Definitely! Dogs with floppy ears (like Cocker Spaniels) or thick hair in the ear canal (like Poodles) are more likely to develop infections as the ears do not get enough air circulation, leading to moisture that favors the overgrowth of bacteria and yeast. Dogs that have had multiple or severe ear infections in the past are also more likely to develop chronic problems due to anatomic changes that occur in the ear with inflammation – such as thickening or narrowing of the canal.

How will my veterinarian help?

Your veterinarian will use a hand-held tool called an otoscope to examine the ear closely. They will collect a sample of the wax from the ear to examine underneath a microscope. This will help your veterinarian pinpoint the cause of the infection so they can prescribe the needed treatment. If your pet has repeated ear infections, your veterinarian may need to do further testing that may include culture of the ear, bloodwork, hypoallergenic food trials, or even provide a referral to a specialist for allergy testing.

What is the treatment?

For most ear infections, treatment is fairly simple. The first step is cleaning out the ear with a flush to remove the excessive wax buildup. After flushing the ears, a medicated ointment is typically applied into the ears daily for anywhere between 7 to 14 days. Sometimes it may be best for your veterinarian to pack the ear(s) with a long-acting ointment that will dissolve over a few weeks.

It is important to note that your veterinarian should always be consulted before administering any products into your dog’s ears, as certain medications can lead to hearing loss if administered inappropriately.

Your veterinarian will ask you to schedule a follow-up visit after treatment has finished to ensure that the infection has completely resolved. If you have any questions about your pet’s treatment plan, please do not hesitate to ask – proper treatment is essential to getting your fur baby back to feeling better as soon as possible!