Q) What causes ear infections?
A) Ear infections in dogs and cats are common. They usually happen when something irritates the ear, causing excess wax production. Bacteria and/or yeast then thrive in this moist environment, leading to further pain, discomfort, and inflammatory changes to the ear canal.
Allergy is a common cause of ear irritation, but foreign material in the ear (such as a grass seed), ear mites, excessive hair, or growths in the ear canal can also cause irritation and secondary infection. In cats, ear mites and allergies are the most common causes of ear infections, but we also see them secondary to polyps or respiratory infections.
Treatment of ear disease involves diagnosing the underlying cause, and treating any secondary infection. This starts with otoscopic examination of the ear canal, and collection of debris to look at microscopically. By doing this, we can best determine what treatments will be most effective.
Often gently cleaning the ear and applying topical treatment is sufficient to resolve the problem. For more severe cases, sedation may be needed to clean foreign material and hair from the canal. Medications including oral anti-inflammatories, antibiotics, or antifungals may be prescribed. If the primary problem is an allergy, then identifying and eliminating the allergen is the ideal treatment. This may require a hypoallergenic diet, or allergy testing. Susceptible animals will probably need routine ear cleanings to prevent further irritation.
Chronic ear disease can lead to severe thickening (stenosis) of the ear canal, making effective treatment impossible. Some pets require surgery to relieve the pain associated with chronic changes to the ear and cartilage. Middle ear infections can also occur which may lead to loss of balance, nausea, and even facial paralysis. In dogs and cats that shake their heads or scratch vigorously, a blood vessel in the ear flap may rupture, causing an accumulation of blood (hematoma) and a swollen tender ear flap which requires medical treatment or surgery.
Warning signs that your pet may have a problem include: shaking the head, pawing/scratching at the ear, tenderness when the ears are touched, redness or swelling of the ear flap, discharge from the ear, odor from the ear, or a head tilt. Ear infections that are treated promptly are much less likely to lead to chronic and painful conditions. It is important to follow up with your veterinarian following treatment to make sure the problem is completely resolved.