Dog Care: Ear Care 101
One of the most common medical problems in dogs is otitis externa, or inflammation and infection of the external ear canal. Unlike people, dogs have a very long ear canal which is divided into two parts: a vertical canal that that travels downward to the horizontal canal which goes straight across and terminates at the dog’s eardrum. The “L” shape of the canine ear canal makes it difficult to visualize the entire canal without the aid of a specialized piece of equipment called an otoscope.
The shape of the canal tends to predispose dogs to “swimmer’s ear” since it is difficult for water to get out once it gets in. The length of the canal provides more surface area for infection and irritation and to complicate matters, some breeds have characteristics that predispose them to having ear problems (such as narrowing of the canals in shar-peis and hairy ear canals which are common in poodles and some terriers). On top of that, many breeds have pendulous ears that cover the ear canal and make for a nice, warm and moist environment, which in turn, promotes the growth of yeast and bacteria by blocking airflow.
It is important to check the ears regularly to see if there is any redness or buildup within the canals. I am fortunate enough to have a dog that seems to be immune to ear problems. Buster is part German shepherd and has partially erect ears so he gets good airflow to his canals and has never had an ear infection in his 10 years of life. However, I still check his ears at least twice a month as it is far better to catch a problem early and treat it before it gets worse. The healthy ear looks pink and clean with no discharge. Inflamed ears have an angry red color accompanied by swelling and narrowing of the ear canal. Discharges are usually signals of infection and the type and color of the discharge can give a strong clue as to what is causing the infection. Yellow is seen with yeast, black crusts usually mean ear mites and a thin brownish discharge is seen with bacterial infections. These are just guidelines and it requires an ear swab taken by your veterinarian and analyzed under a microscope to determine the cause. Mixed infections are very common.
The most common cause of otitis externa is a yeast infection called Malassezia pachydermatitis. A yeast infection can typically be recognized by thick yellow-tan exudates that build up within the ear canal. It usually has a very pungent and characteristic odor. Treatment involves cleaning the ear with a gentle ear cleaner and then application of antifungal medication.
Bacterial infections are commonly associated with otitis externa. Staphylococcus is the most common although other bacteria such as Pseudomonas may be involved. It is important to note that bacterial infections are secondary; they occur as a result of otitis and are not a primary cause. Bacteria are normally found in the ear canal but when the ear canal becomes inflamed the bacterial population skyrockets and tends to get out of control. Treatment involves determining the underlying cause of the otitis and application of an antibacterial medication. If the infection is really bad then your veterinarian may start your dog on oral antibiotics in addition to the topical antibiotics.
Ear mites are typically seen in puppies and young dogs. They are very itchy and the dog may scratch up the ear pretty bad in an attempt to relieve the itching. Black or reddish brown crusts can be seen on the earflap and sometimes on the neck as well. Ear mites are very contagious if one dog in your household is diagnosed with ear mites any other dog or cat in your household must be treated as well. Treatment involves cleaning the ear with a gentle ear cleaner or mineral oil and application of an anti-mite medication. The environment must be treated as well; bedding should be washed, carpets should be thoroughly vacuumed and consider use of flea bombs which are also effective against mites.
Other causes of otitis are grass awns such as foxtails, food, or contact allergies and obstructions such as a growth, polyps or too much hair in the canal. Recurrent ear infections are likely to have an underlying cause such as food allergies or hypothyroidism. If your dog keeps getting ear infections then a full work up is indicated to see if an underlying condition is causing the problem.
Check the ears whenever you see your dog acting painful, scratching at the ears and shaking his head. Head shaking can rupture the cartilage in the ear flap resulting in bleeding under the skin, a hematoma can form and will feel like a fluid filled pocket on the ear flap. This is very painful and needs to be treated by your veterinarian as soon as possible. If not treated otitis externa can spread to the middle ear causing problems such as a ruptured ear drum and neurological signs such as head tilt, loss of balance and circling because of disruption of balance centers in the ear. Long-term changes to untreated or recurrent otitis include thickening of the canal and increased activity of wax producing glands in the ear resulting in conditions favorable for even more bouts of otitis. This is a vicious cycle and sometimes surgical removal of the ear canal is necessary with severe chronic cases. This is another good reason to check the ears often and treat problems early.
Generally once a dog has a case of otitis I recommend the ears be cleaned once or twice a month for maintenance after the otitis clears up. Your vet may recommend something different depending on how bad the otitis was. Cleaning the ears regularly dramatically decreases the chance of it recurring. General ear cleaners can be found in any pet store or veterinary clinic. To clean the ear, apply a few drops of cleaner into the canal and gently massage the base to spread it around. Then take a cotton ball and swab out the canal. Do not use Q-tip applicators as you may push debris deeper into the ear or cause trauma to the canal or eardrum.
If your dog has hairy ears then use tweezers or a forceps to grasp and pluck the hairs. It is important to be gentle when cleaning ears and not to be too overzealous while cleaning as this can irritate the ear canal setting it up for infection and inflammation. Dogs that swim should have their ears cleaned after swimming. Be careful not to get water in the ear while bathing your dog. You can use cotton balls to protect the canal while bathing, just remember to take them out when you’re done. Make a habit of checking your dogs ears frequently and see your regular veterinarian if you notice a problem.
About Dr. Kristy ConnDr. Kristy Conn graduated from Ross University School of Veterinary Medicine and did her clinical year at the University of Minnesota Veterinary Teaching Hospital where she fell in love with emergency and critical care medicine. She has practiced emergency medicine at various clinics almost exclusively for the past 10 years, in addition to volunteering in shelter medicine, checking on the health of arrivals and providing low cost spay/neuters and immunizations to recently adopted animals. She is a member of the National Animal Health Emergency Response Corps which helps provide veterinary care to animals affected by disasters such as Hurricane Katrina. She resides in Long Island with her beloved mixed breed dog named Buster.
