Ear Infections: Diagnosing, Treating, and Cleaning
Ear infections are one of the most common conditions we treat at Clarendon Animal Care. It is helpful to understand the anatomy of the ear and potential underlying causes when managing a pet with ear infections, especially if they are recurrent.
There are many potential predisposing factors, including:
Allergies (environmental, fleas or food)
Anatomy (certain breeds have anatomical characteristics that cause complete occlusion of the canal when even mild inflammation is present)
High humidity/heat, swimming, retained water in the ear canal
Trauma to the ear canal (e.g.: overly aggressive cleaning or inappropriate hair plucking)
Polyps
Tumors
Foreign objects
Medical conditions (diseases that compromise or alter immune-system function)
Anatomy of a dog’s ear
We break the ear down to three basic regions:
External ear (horizontal/vertical ear canals)
Middle ear (within the tympanic bulla)
Inner ear (where the hearing organs are located)
Ear infections can thus be broken down into external ear, middle ear (more like what a human gets when they get an ear infection), and rarely inner ear infections. The incriminating bugs for these infections can range from yeast, bacteria or mites...and they are all treated differently. This is why your veterinarian will typically take a swab from the ear and examine it under the microscope -- they are trying to identify what organism(s) and in what numbers are present. In some cases of bacterial otitis, a culture and sensitivity is needed to find out what specific type of bacteria is present and to help guide antibiotic selection.
The real kicker with ear infections is that there is almost always an underlying cause - meaning the organisms we find in those ears are rarely the primary problem (the exception would be mites). To keep the infections from coming back and to facilitate clearing of the infection, the underlying problem should be looked for and addressed (or at least a management strategy put in place).
Otits Externa (inflammation/infection of the external ear canal) is the most common presentation of an ear infection in both dogs and cats. These can crop up as a new (acute) infection, a recurrent infection or a chronic (never fully cleared) infection.
Management of otitis externa involves treating the infectious component as well as addressing the underlying factors as well. Ear cleaning is often a mainstay of managing both the infectious component as well as helping managing some underlying factors (such as allergies and anatomical predispositions or to dry the canal following a swim). Because we find that a lot of folks were never taught how to correctly clean their pet’s ears we’ve put together a video!
When ear infections are appropriately identified and addressed, we can often prevent or minimize recurrences - though for some pets this means a chronic/maintenance strategy is put in place. In cases where a pet has had severe chronic inflammation & infection of the external ear canal, scarring/fibrosis and mineralization of the ear canal may occur - making medical management far more difficult (and sometimes impossible). In some of these most severe cases surgical removal of the external ear canal is indicated to provide lasting relief to the patient - this is called a total ear canal ablation or TECA.
Otits Media (inflammation/infection of the middle ear) - this often goes hand in hand with chronic bacterial Otitis Externa and the ear drum in these cases if often ruptured or severely thickened/abnormal. In some cases, we need to manage pain/infection/inflammation before we can even see the eardrum - and in these cases follow up/rechecks are very important so that we can really evaluate what is going on down in that canal.
In addition to causing recurrent symptoms of the external ear canal, these middle ear infections can actually cause neurologic symptoms (generally problems with balance), or pain opening the mouth. Otitis media often requires systemic medications, but in many cases anesthetic procedures to thoroughly evaluate, obtain biopsies and/or cultures and clean out the middle ear may be needed to get them to clear and heal. In some cases, aggressive surgical procedures to open the tympanic bulla (bulla osteotomy +/- TECA) may be indicated.
So what are the take-aways from this?
It is important to determine if your pet’s ear infection is caused by yeast, bacteria, mites, or other so that the infection or inflammation can be treated most effectively.
It is also important to identify predisposing or underlying factors so they can be addressed or chronically managed.
Ear drum assessment is important, especially if there is concern for middle ear involvement (sometimes this may require light sedation in order to fully assess). If the middle ear gets involved topical medications alone rarely work.
Work with your veterinarian to come up with a chronic management plan to help prevent/reduce recurrences, and if you have any questions about the plan be sure to ask your veterinarian!
Written by Dr. Natasha Ungerer