What is Otitis Externa?
Otitis externa is an inflammation or infection of the outer ear canal. The outer ear canal is an L-shaped tube, opening out to the ear flap on the outside, and on the inside, it ends in the eardrum.
Causes
We see a lot of dogs with ear infections in the Sutherland Shire. Ear infections are most commonly caused by allergies (as ear canals are part of the skin), including pollen allergies and food allergies.
Other causes of ear infections include ear mites, foreign bodies (such as grass seeds), metabolic or hormonal diseases, autoimmune diseases, or growths.
Factors that contribute to ear problems include heavy, floppy ears, hair in the ears, trapped moisture, and improper ear cleaning.
Symptoms
Ear infections and inflammation can cause a lot of discomfort to our pets. The ears can be red, swollen and painful to touch. The skin may be scaly or flaky. Depending on the (secondary) infection there may be a smell or discharge as well. Dogs may shake their heads or scratch their ear(s). They can even be so irritated that blood vessels inside the earflap can burst, causing a puffy blood filled ear, also known as aural (ear) haematoma. More chronic ear problems may present as thickened narrowed ear canals, and thickened, maybe grey coloured skin on the inside of the ear flap and ear canal. The ear flap and ear canal can even be ulcerated.
The discharge can vary from light yellow or creamy to dark brown to black coloured, and with a greasy, crumbly, waxy or moist consistency, the smell can vary from “yeasty” to “purulent”.
Why visit a Vet
A veterinary consult is imperative to diagnose what is going on. Different causes need different treatments, and secondary infections can include various bacteria and yeast. Diagnostic tests needed to come to a diagnosis is a thorough history of prior skin and ear problems, otoscopy of the ear canal (sometimes this is not possible without sedation or anaesthetic), and microscopic examination of the contents of the ear canals. Sometimes we even need to send a swab off to pathology to identify the offending organisms in the ear and check their antibiotic sensitivities and resistances.
Underlying causes, such as hypothyroidism, or skin allergies, need to be addressed, as well as the secondary infections. In some cases, the underlying disease can only be managed, not cured, and the pet is at risk of recurrent flare-ups. This means follow up visits are very important, so treatments can be adjusted as needed and hopefully complications can be avoided or minimized.
Complications
Complications of otitis externa can include a ruptured ear drum, otitis media (middle ear infection, which can present as a head tilt, incoordination, and even vomiting) or even otitis interna (inner ear infection), chronic changes to the ear canal causing narrowing or closing of the canal. These cases may even end up causing deafness, and/or needing surgery.
Treatment
The best way to treat otitis externa is with topical ear medication. Unfortunately, in many cases, this can be difficult if the patient has learned that touching the ears is painful. In certain cases, a new product can be used where 2 single ear applications 1 week apart is sufficient to treat the ear(s)! For more information, or if you have any concerns about your pet’s ear or other health issues, please contact the friendly staff at Cronulla Veterinary Clinic on 02-9527 2604 or email us at cronullavetclinic@telstra.com