OTITIS EXTERNA
Otitis Externa (infection of the external ear canal) is more common in dogs than other domestic animals. The highest incidence is in those dogs with hanging ears and hair growth in the external ear canal, such as cocker spaniels and springer spaniels. Swimming also puts dogs at risk for ear infections. An ear drying solution may be needed for dogs that swim, to prevent water from sitting down inside the ear canal and leading to infections.
COMMON CAUSES
Some of the agents commonly incriminated as causes of external otitis are: water, soap, oil, powders, loose hair, grass lawns (little, sharp bits of plant material), parasites, tumors, accumulations of wax, and accumulations of epithelial cells. If any of these get down inside the ear canal they can cause irritation which then can lead to infection. Multiplication of bacteria and yeast is favored when the ears are inflamed due to any of these various irritants.
Reoccurring or chronic ear infections are often the result of an underlying problem such as allergy or low thyroid levels. Both food allergies and allergies to airborne pollens, molds and dust mites can lead to otitis. (German Shepherds are especially prone to ear infections due to food allergy.) Most dogs with allergies have other symptoms besides ear infections, especially itchy feet and face. Whereas allergies in people usually lead to hay fever symptoms, allergies in dogs usually lead to itchy skin.
SYMPTOMS
The itching and pain of otitis externa causes the animal to be restless, to rub its ears against objects, to shake and scratch its head, or to tilt its head to the affected side. The ears may look red and sore or have a foul odor. One or both ears may be involved. The inflammation is aggravated by the head shaking and scratching, and the skin may become abraded from scratching, leading to a traumatic dermatitis. If a blood vessel in the ear flap breaks from excessive head shaking a “hematoma,” or large blood filled lump on the ear flap, can occur. Hematomas require surgery to repair.
TREATMENT
Treatment usually consists of a thorough, gentle cleansing and removal of ear discharge and hair from the ear, followed by ear drops or ointment, and often oral antibiotics as well. A sample of the discharge from the ear is often examined under a microscope to identify the cause of the infection, so the proper medication can be prescribed.
The ear(s) should be cleaned as often as necessary to keep the ear canal clean. Ear ointments are not very effective if the ear is filled with pus or wax. Squirt a generous portion of ear cleaner in the ear canal, massage the ear & then wipe out the excess, along with the wax or debris, with a Kleenex, cotton ball or Q-tip. Be careful not to poke Q-tips too far into the ear to avoid damaging the ear drum.
Most ear cleaners are acidic in pH and this can cause the antibiotics in some ear ointments to be less effective. For this reason it is sometimes recommended to clean the ears out first and then wait 1-2 hours before putting the antibacterial/antifungal ear drops into the ear. The amount of medication used in the ear should be enough to lightly coat the entire lining of the ear canal. Usually this is one good squeeze of the ointment bottle or tube. The ear should make a squishy noise when you massage the base of the ear. The massaging ensures that the ointment is evenly distributed throughout the entire ear canal.
If the infection is severe we may prescribe oral medications as well as ointment and ear cleaning.
In prolonged or severe cases, bacterial culture and sensitivity may be required, as may surgery. The ear may need to be flushed and cleaned under anesthesia or the ear canal may need to be rebuilt to allow better air circulation into the ear canal. If the ear infections keep coming back despite proper treatment we will start to look for other underlying problems. A hypoallergenic diet, thyroid testing or a medication trial
for allergies may be needed.
PREVENTION
Keep water, soap and all foreign objects out of the ear canal unless prescribed by the doctor. A routine weekly ear cleaning with a solution made for that purpose is a good habit to get into. All dogs should have routine inspections of the ear canal to check for discharge or odor, and to ensure that the canal is not obstructed. Some breeds need the hair regularly plucked from the canal, but in others plucking will cause problems.
One common mistake is periodic haphazard medicating of an infected ear canal. If an infection is not completely eradicated, and is chronic or recurrent, scar tissue will build up in the ear canal and the bacteria will become resistant to antibiotics. To prevent this, always medicate the ear as prescribed, and have the ear rechecked by your veterinarian to ensure that it has healed properly.