April 28, 2013
Driving down a country road in our family vehicle, a loud diesel truck, we came upon a dog running alongside the road. As we slowed our speed, he began to run into the middle of the road, very focused on his target ó a rabbit ó and he soon realized that he was no match for the agility of his prey. Defeated, he turned around and almost jumped out of his skin as he saw our truck creeping along behind him. His face, sunken and gray, showed his age. Clearly, not even a small portion of his hearing remained.
In the prime of his life, this old dogís ears could detect frequencies two times greater than the upper range of a humanís ears. Frequency of sound is the rate at which the sound waves vibrate; therefore, a shrill whistle is a higher frequency than a tuba, for example. By the way, cats can detect frequencies almost three times greater than the upper range of a human. Imagine all the things our pets hear that we will never know or understand. They use their amazing senses to hunt, survive, play, work, and protect us ó which is why we must know how to protect them against diseases that can cause ear damage and hearing loss.
Your petís physical examination is the first line of defense against ear problems. A veterinarian is trained to detect signs of ear discomfort or infection; however, maybe you have noticed signs of your pet shaking his head, scratching around his ears or neck, rubbing his head on the carpet, or you have noticed a bad odor coming from around his head. These all may be signs of ear disease, and should be brought to your veterinarianís attention.
Yeast infections are the most common ear problems I see in practice, and are more common in dogs. An underlying cause such as allergy or moisture buildup changes the environment inside the ear canal, allowing the yeast (Malassezia) that is normally present in small numbers to take over and multiply out of control. Signs of a yeast infection include dark brownish waxy ear debris, redness and irritation inside the ears, and an odor characteristic of a brewery! Pets can also have bacterial ear infections (for example, Staphylococcus or the more resistant Pseudomonas), and the odor is usually very foul.
Your veterinarian can diagnose and treat your petís ear infection properly, as well as address any underlying causes for the infection. I encourage pet owners not to try home remedies often used for humans, such as hydrogen peroxide or sweet oil, to clean their petsí ears. Cleaning the ears with a harsh or ineffective substance will only worsen the problem in the long run. Complications of an untreated external ear infection include chronic thickening and calcification of the ear canal, spread to the middle and inner ear (this can affect balance and coordination), aural hematoma (a blood-filled ear flap due to damage from head shaking or scratching), and hearing loss. Repeated ear infections due to an unaddressed food allergy or environmental allergy can also lead to these unwanted complications.
Ear mites (Otodectes) are parasites that can cause ear infections if not treated. These eight-legged critters are highly contagious and most common in outdoor cats and young animals (kittens, puppies and rabbits, too) that have been in close contact with one another. Ear mites live on the skin of the ear canal, happily munching on ear wax and skin oils. The characteristic dry black (ďcoffee groundĒ) discharge of an ear mite infestation is composed of wax, blood, inflammatory products, and the mites. Examination with an otoscope or microscope at the clinic can easily diagnose the irritating bugs ó donít assume your pet has ear mites and purchase an over-the-counter product, because you may be wasting your efforts on a yeast infection. Single dose products are available from your veterinarian, making ear mite treatment much easier.
With summer coming, it is important to maintain our petsí ear health, especially dogs that enjoy swimming. Has your veterinarian recommended routine ear cleaning for your pet? If so, dust off that bottle of ear cleaning solution on the shelf and check your petís ears. Mild discharge or odor, or a recent swim or bath call for a good cleaning: apply a liberal amount of cleaning solution into the ear canal, then massage the base of the ear for 10 to 20 seconds. With your finger and some cotton, wipe as deep into the ear as your finger will allow (donít put Q-tips where you cannot see!). Repeat the process if necessary, then allow head shaking to get rid of the excess cleaner and wax. This simple procedure can make a huge difference in your petís comfort, senses, and overall quality of life!
Dr. Sara Smith is an associate veterinarian at Delphos Animal Hospital.