A wise old doctor once said, "Never put anything in your ear smaller than your elbow." This doctor could have been a veterinarian instructing you about ear care in the dog. Without a doubt, one of the most common problems that crosses the veterinarian's exam table is otitis externa (infection or inflammation of the external ear canal). Surprisingly, most ear infections can be forestalled by proper preventative care by the pet's owner. Often pet owners unknowingly make the problem worse by inappropriately treating the ear with improper medication or by traumatizing the ear during cleaning. The best way of preventing this is to take your dog to your veterinarian once you notice any ear problems and learn proper ear cleaning techniques.
Now HEAR This!
I once had a pet owner complain that she had been treating her dog for what she thought were ear mites (a parasite found in the ear) for weeks and had not been successful at resolving the problem. Upon examination of her dog's ear canal, I found several pieces of spear grass embedded near the ear drum and gently extracted them. All the ear mite medication in the world would not have re-solved the problem.
To understand the dog's ear problems better, we must initially understand that the dog's ear canal is anatomically different than that of the human ear. Unlike the human ear, the dog's ear has two compartments. Beginning at the opening of the ear canal, the vertical canal travels downward towards the dog's jaw. Then it makes a 45 degree turn and travels horizontally towards the ear drum. This makes visualization and treatment of the entire canal more difficult. Also, as a rule, most breeds have a much longer ear canal than humans. These differences predispose the dog's ear to infection as well as make treatment more difficult.
Dogs with long, pendulous ears, such as Cocker Spaniels, Labrador Retrievers, Basset Hounds and Irish Setters, certainly are more predisposed to ear problems than those breeds with short, erect ears. As the ear folds, it covers the ear canal and prohibits air from entering and drying the canal. The result is a moist, warm ear canal that is a perfect environment for organisms to grow.
Inflammation of the ear canal, or otitis externa, can be caused by a number of factors, such as parasites, microorganisms, foreign bodies, tumors, and underlying dermatological (skin) disease. Ear mites are parasites that often can cause otitis externa. However, the incidence is much lower than often thought. In my experience, less than 10 percent of all ear problems in dogs that I have treated are the result of ear mites. Ticks and fleas are other examples of parasites commonly found in canine ear canals.
Ear mites can be problematic, however. An elderly gentleman once explained that he thought his dog was "going crazy." He said his old setter would sleep by the fireplace. Suddenly it would jump up yelping and begin to run around the room in circles. After several minutes of hysterical commotion, the dog would lie down again and go back to sleep.
After pondering the situation, I examined the dog's ears and found a heavy infestation of ear mites. It appeared that as the heat from the fire warmed the dog's ear canals, the mites would became agitated and began to move around. As the old setter would run around the room, the ears would cool down and the mites would stop their activity. Then the dog would return to the fireside.
An important point to remember is that ear mites are parasites. Therefore, for your dog to have ear mites, it must have had direct contact with another pet infested with ear mites. So if your veterinarian diagnoses one animal in your house with ear mites, it is best to have all of your animals examined for possible infestations.
Dastardly Yeast Infections
The most common cause of canine ear problems that I see is caused by microorganisms, particularly yeasts. Malassezia pachydermatitis usually is the culprit, and it loves to proliferate in warm, moist environments such as the dog's ear canal.
Owners will notice the dog shaking its head or scratching at its ears. A good sniff near the ears usually verifies a problem, as most infectious otitis ears are quite pungent. Certain bacteria such as Staphylococci, Streptococci, E coli, and Pseudomonas spp also can cause infections in the dog's ear, and in many cases both bacteria and yeast are present. If the infection persists, the ear canal will become inflamed and often discharge a purulent exudate, a pussy substance.
Your veterinarian usually will take an ear swab and examine it under a microscope to determine the exact cause of the infection. This will enable a specific treatment plan to resolve the problem. Often, treatment will include flushing the ear canal with an antimicrobial solution and drying agent. An anti-inflammatory injection is then administered to reduce swelling and relieve the pain. The appropriate topical medication also will be dispensed for further treatment by the pet owner. Remember, all ear infections are not caused by the same microorganism; therefore, treatment without proper examination is strictly guessing.
As a pet owner, it is important to know that persistent or recurring ear infections in a dog commonly are manifestations of other concurring disease processes. Allergies and hypothyroidism are good examples. Systemic allergies often cause dermatitis and itching in the ear canal, which predispose self-trauma and subsequent ear infection. Hypothyroidism may manifest itself as increased thickness of the skin and continual release of exudate in the ear canal, which favors an environment for otitis externa.
Practicing Proper Ear Care
Proper ear care for the dog can often prevent recurring infection. Dogs with a history of ear disease require routine cleaning of the canals. I recommend plucking all hair that grows in the canal. Hair impedes air flow into the canal that tends to keep the canal dry. Common household tweezers or forceps work well and usually are well tolerated by the dog. Be careful not to grasp the skin of the canal. After hair removal, flush the ear canals with a commercial ear cleaner. These products can be found at most veterinarian clinics or pet shops. After flushing, gently massage the base of the ears to distribute the solution around the normal ear folds.
Most ear cleaners have several functions. They not only clean the ear canal but also have an agent for liquefying exudate, drying the ear canal, and changing the pH (acidity) in the canals. Most microorganisms prefer an environment that is alkaline; therefore, most ear preparations have an acid base. Frequency of treatment will vary among individuals, but once a week during the warm months is a good rule of thumb for those dogs that have had problems with infected ears. Also, any time your dog is bathed or enters the water, an ear cleaning solution should be administered immediately afterward. This preventative is similar to what humans do to ward off "swimmer's ear." Dogs without a history of ear problems may be treated with an ear cleanser after bathing.
It is not wise to use cotton tip applicators in the ear canal. This can be quite painful to the dog. Also, I don't recommend using alcohol in a dog's ear. Alcohol will dry the ear, but if there is inflammation or small scratches in the canal, the alcohol will burn and cause tremendous pain and further inflammation. If you must use a product from the shelf at home, use white vinegar diluted 50:50 with water.
Good preventative ear care can eliminate needless trips to your veterinarian and save a lot of discomfort for your dog. Watch your dog carefully for scratching at its ears or shaking its head. Have your groomer check for an ear problem each time you take your dog in, and at home take the time to check your dog's ears for redness, odor or the presence of exudate. If you determine there is a problem with your pet's ears, don't wait. Let your veterinarian do a thorough examination and direct specific treatment before the problem worsens.
Canine Ear Checklist
You may need to take your dog to the vet for a thorough examination if it:
Shakes its head or scratches its ears
Lives with other pets with parasitic infestations
Exudes a pungent odor from its ears
Has long, pendulous ears
Lives in a humid environment
Loves to swim or bathe
Has a history of recurring ear infections
Dr. Thomas has been a practicing veterinarian in Lewisville, Texas, for 15 years. He has written numerous articles about pet health published in several magazines and newspapers. This article was published in Dog World magazine, November 1996 edition.