Otitis externa is an inflammation of the outer ear and ear canal and is the most common disease of the ear canal in dogs.Otitis media, meanwhile, describes inflammation of the middle ear.
Inflammation of outer ear canal or otitis externa is more common in dogs with floppy ears since air flow is limited and a warm, moist environment built up in the ear, which is conducive to infection. The infection starts with change in microclimate in the ear . This causes gland linings to enlarge and produce excessive wax. Production of fibrous tissues by skin and inner skin causes narrowing of the ear canal. It is normally a secondary symptom of another underlying disease, such as an infection. Pain, itching and redness are signs of otitis externa. If the condition becomes chronic, it may result in ruptured ear drum and otitis media.
Otitis media is usually an extension of the otitis externa which causes ruptured ear drum that separates external and middle ear.
Dogs with long, floppy ears such as spaniels and retrievers, and dogs with hairy external canals, such as terriers and poodles, are more susceptible.
Pain, head shaking, scratching at the external ear flap and bad odor are the most common signs of otitis externa and media. Other signs include redness and swelling of the external ear canal, scaling skin or obstruction of the ear canal.
Typical signs of otitis media or interna include tilting the head, anorexia, uncoordination, and occasional vomiting.