Otitis (Ear Inflammation)
By Dr. Karen Burgess

 What is otitis?
Otitis is better known as an ear infection.  Otitis externa would be infection of the external ear, media the middle ear, and interna the inner ear (where the hearing apparatus is located).

What are the signs of otitis?
Dogs and cats with otitis may present with ear redness, discharge or odor.  Some may rub or scratch at their ears.   Owners may notice pain or reluctance to having the head and ears pet.

How do dogs and cats get otitis?
There are a variety of reasons pets get ear infections.  Bacteria and yeast are common causes, but are typically considered secondary to some other pre-existing condition.  The wax, moisture, and oils found in the ear canal contribute to problems by “feeding” the infection.  Anatomically, some breeds with narrow ear canals, floppy ears, or a tendency toward excessive fur in their ears may have more frequent ear infections.  Ear mites or foreign bodies can lead to secondary infections of the ear.  Pets that have had recurrent or untreated previous ear infections may develop scar tissue making future episodes of otitis more likely.  For pets experiencing repeated infections, underlying allergies (food or inhalational) are common and should be considered as a primary cause.

How is otitis diagnosed?
Physical examination of the ear canal will show discharge and inflammation associated with otitis externa and media.  Otitis interna requires advanced imaging and anesthesia for diagnosis.  Cell samples are taken from the ear canal to examine microscopically for the presence of bacteria and/or yeast.  In some cases a culture of the ear may be recommended to determine specific bacterial presence.  Debris can also be evaluated for evidence of ear mites and their eggs.  If underlying allergies are suspected a food allergy trial, antihistamines, or referral to a dermatologist for skin testing may be recommended.

What is the treatment for otitis?
Ear infection treatment varies depending on severity.  Cleaning of the ear canal may be recommended, but in some cases is considered too painful and irritating initially.  Ear medications are often instilled into the ear by owners at home once to twice daily.  Rechecking the ear for complete response in one week may be recommended.  In some cases wax impregnated medication may be instilled in the veterinary office.  For ears experiencing chronic disease surgery may eventually be indicated.

What are possible complications from otitis?
Vestibular disease (similar to vertigo in humans), ear hematomas (broken blood vessel in the ear flap), and hearing loss are all possible sequel to otitis.

How can otitis be prevented?
Prevention of ear infections is most successful when underlying disease is treated and predisposing conditions controlled.  For some pets, preventative ear cleansings may be beneficial on a regular schedule or after swimming.