Dogs that have otitis and/or ear infections that are either neglected or not treated successfully can have a variety of potential complications. Otitis refers to inflammation in the ears and may occur for many different reasons. The term "ear infections" is a bit more specific and refers to an actual infection—either bacterial, fungal or parasitic—rather than simple inflammation.
Though there is technically a difference between otitis and ear infections, the two are often present simultaneously, and they cause similar complications.
What Untreated Ear Infections May Lead To
Ear infections that are not treated can spread from the outer part of the ear into the middle or inner ear of the dog. When the infection or inflammation spreads to the middle ear, it is termed otitis media. When the infection or inflammation spreads to the inner ear, it is known as otitis interna.
Otitis media causes symptoms that include paralysis of the dog's facial nerves, deafness, keratoconjunctivitis sicca ("dry eye") and Horner's syndrome. Horner's syndrome consists of drooping of the upper eyelid, prolapse of the third eyelid, the recession of the eyeball or constriction of the pupil.
Vestibular disease results when otitis interna occurs. The vestibular disease causes symptoms such as a head tilt, loss of balance, incoordination and uncontrollable shifting eye movements known as nystagmus.
Complications From Unresolved Chronic Otitis
Chronic otitis that is unresolved can cause proliferation of the lining of the ear canal, which leads to a narrowing of the car canal. Ear canals that are drastically narrowed are known as stenotic ear canals. In some cases, the ear canals become so stenotic (narrow) that it is impossible to treat them medically. In this situation, surgery may be the only option for your dog.
Ear Hematomas Lead to Cauliflower Ear
Ear hematomas occur as a result of trauma caused by your dog shaking his head excessively or scratching at his ears. They are also known as auricular hematomas. An ear hematoma is a pocket filled with blood that occurs on the ear, almost always on the flap of the ear.
Normally, a hematoma forms on only one ear but it is possible to see hematomas on both ears. Though hematomas are most often associated with inflammation and/or infection in the ears, this is not always the case. Sometimes, hematomas can form on ears that appear to be perfectly healthy.
Hematomas are unsightly, but when left untreated, many heal themselves. However, when they do it, the ear sometimes reabsorbs the blood unevenly, and the dog is stuck with a "cauliflower ear" for life.
Otitis Media And Interna In Dogs. Veterinary Manual
Dealing With the Painful and Irritating Chronic Otitis Externa Cases. University of Illinois at Urbana-Champaign College of Veterinary Medicine, 2020
Disorders Of The Outer Ear In Dogs. Veterinary Manual