Ear Infections

Otitis Externa

Otitis externa is the technical name for an external ear infection and resulting inflammation. The external ear canal is often affected. In severe cases the eardrum may rupture and cause a middle and/or inner ear infection as well. In the worst case this can cause permanent facial nerve paralysis, head tilting or loss of balance.

What makes ear infections likely to occur?

Ear infections are common in dogs but they can occur in cats as well. There are many different causes:

• Foreign objects – grass awns (foxtails), ear mites, ticks, fleas

• Water – moisture from swimming or bathing

• Allergies – Atopy (inhalant allergy), food allergy

These diseases cause the skin to be itchy and the ears are then prone to infection.

• Hormonal disorders – Hypothyroidism (low levels of thyroid hormones) compromise the body’s natural defenses to ear infections

• Growths or masses in the ear canal – lead to obstruction of air flow

• Breed Differences – dogs with long floppy ears like spaniels, poodles, retrievers, etc. have impaired airflow to the ear canal. Also, breeds that have abundant hair growth in the ear canal like poodles, bichons, etc. have a more favorable environment for developing ear infections.

What causes ear infections?

YEASTS like Malasezzia and Candida are most commonly involved along with BACTERIA like Staphylococcus, Pseudomonas and Proteus. EAR MITES (Otodectes) may also be involved, especially in puppies and kittens.

Normal dogs may have occasional yeast and bacteria in their ears without problems, until moisture or other irritation sets up favorable conditions for otitis to develop.

How is otitis diagnosed?

Generally, a history of head shaking, pain and scratching along with physical findings of odor from the ears, redness and discharge in the ears leads to a diagnosis of otitis. In most cases, a swab is used to collect some debris and a smear is made to examine microscopically. Occasionally a culture is performed to identify the causative bacteria.

How is otitis treated?

Treatment of otitis depends on what initiated the disease. Generally a topical medication is used in the ears and occasionally an oral antibiotic is prescribed as well. Anti-inflammatory medications are often prescribed to make your pet more comfortable. If your pet has tested low for thyroid hormone levels, a thyroid supplement is given. It is important to treat the ears even if the ears look better earlier. This will ensure that the problem will resolve completely and help avoid relapses.

How can otitis be prevented?

In general, otitis caused from moisture or foreign objects is prevented by using a cleanser/drying agent for the ears after swimming or bathing. If excessive hair grows in the ear canal, this hair must be removed to allow adequate air flow into the ears.

Routine cleaning of the ears with specially formulated ear cleaning solutions is helpful in almost all cases. The frequency depends entirely on the individual pet and ranges from weekly to monthly. Many pet owners find just after bathing to be an ideal time to cleanse the ears.

We hope we can help you prevent the discomfort of future ear infections in your pet.