The L letter-shaped portion of the ear of your pet that you can see from the outside is vertical shaped and is only the half of the ear canal. This vertical canal leads to the horizontal canal which eventually ends at the eardrum (tympanic membrane).
The external ear canal can become inflamed due to allergies, ear mites, foreign bodies, and infections. This inflammation of the external ear is called otitis externa. Symptoms of otitis externa include head shaking/rubbing, redness within the ear canal, and odor. Otitis externa can be asymptomatic i.e., showing no symptoms of disease and is diagnosed incidentally by your vet or the groomer. Physical examination includes obtaining a sample of the waxy discharge to detect the presence of mites, yeast, and bacteria. This also helps in determining the extent of infection.
Treatment of otitis externa in most cases includes removing the inflammatory debris using ear cleaner and use of topical medication to fight the infection. Follow-up requires repeated physical examinations to make sure the infection has been resolved completely. If left untreated, the infection can extend to the middle ear causing hearing impairment and loss of balance.