Evaluation of the Patient with Ear Disease

Examination of the Ear

The first step in approaching ear disease is to do a good physical examination with special attention paid to the skin and coat quality.  Often the clues needed to determine the primary cause of ear disease will be found through subtle clues found during the physical exam.  Next, obviously the ear must be thoroughly evaluated.  Without thorough and adequate visualization of the ear canal and ear drum, as well as evaluation of samples collected from deep in the ear, appropriate and complete treatment of the ear disease can not be done.

Examination of the ear canals and ear drums of dogs and cats can be extremely frustrating and painful to the pet that is suffering from this disease.  Simply manipulating the ear or inserting the otoscope cone into the ear canal of a dog or cat with a painful ear can cause extreme pain and may result in aggression toward the veterinarian.  After such an experience many pets are extremely reluctant to allow their owners to treat their ears at home, thus the ear disease becomes chronic and the animal’s suffering continues unabated.  Because appropriate treatment of diseased ears can only be done after a complete examination and evaluation, sedation or anesthesia is often required in the painful patient.  Examination can also be hindered by swelling and accumulation of inflammatory material, such as mucus and pus, within the canals.  Very inflamed ears may need to be treated with topical or systemic steroids for a week or two in order to allow for better visualization.

Cytology and Culture

Microscopic evaluation of the secretions from deep in the ear canal is vital when trying to identify a patient’s current condition, as well as underlying causes.  It is necessary to know what kind of infectious organisms there are, if any, so treatment can be aimed specifically for each patient.  It is also essential to recheck these cytologic examinations during treatment so as to monitor progress.  In addition to assessing response to the chosen treatment, it is important to monitor populations of organisms, since they can change and require different medications.  Cultures of these organisms are also needed in some cases in order to determine susceptibility and resistance to drugs.  In order to obtain these samples in painful dogs and cats, sedation or anesthesia may be necessary.

Flushing the Ears

After the type of disease affecting the ears is determined, the next step is to clean the ears.  Adequate evaluation of the skin of the canals and the status of the ear drum can only be done after all the accumulated material has been removed.  It is also important that medications are applied directly to skin.  In most cases cleaning at home by owners is initiated.  If the material in the canals is too tenacious to be removed by treatments at home, or if the patient is too painful for this type of cleaning, we will need to anesthetize in order to flush out the ears.

Evaluation of the Ear Drum

The very thin ear drum is the only thing separating the external ear from the middle ear.  Because middle ear disease is quite serious and treated entirely differently from external ear disease, it is essential to evaluate the integrity of the ear drum. 

Medical Imaging

Radiographs (x-rays) are often necessary to determine presence of middle ear disease.  Because of the precise positioning required to acquire these views, anesthesia is always necessary, even in the most cooperative of patients.  Radiographs are often taken at the time of deep ear flushing in order to avoid an additional anesthesia procedure.  Occasionally, advanced imaging such as computer tomography (CT) or magnetic resonance imaging (MRI) is needed in order to evaluate the skull and surrounding tissues.

Skin, Blood and Urine Testing

Because there are so many primary causes of ear disease that don’t originate from the ear itself, we need to evaluate other systems.  Skin scraping or cytology is frequently done to look for parasitism or infection.  Based on a patient’s breed, age or physical examination findings, the doctor may need to do blood and urine tests in order to evaluate endocrine function.  Although these tests may seem unrelated to ear problems, they can be invaluable for diagnosis and treatment.

Re-evaluation

One of the most critical aspects to the resolution of ear disease is regular re-evaluation.  Multiple examinations and cytologies are needed in every case of ear disease.  The more complicated or chronic cases may require more than one deep flushing and follow-up radiographs.

Ear disease is complicated and can be frustrating for doctors, owners and patients.  The key to successful treatment is teamwork, dedication and perseverance.