Why Does My Dog Get Ear Infections?
By: Dr. Amanda Landis-Hanna
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Happy National Pet Week! In honor of all of our favorite companions, I thought I would tackle a common issue … ear infections. Today’s Medical Monday is brought to you by Joel, a mixed breed puppy recently adopted by my Voyce coworker, Laila. Joel is a great dog, well behaved and laid back. But he is apparently predisposed to ear infections. This inclination is not uncommon, and one I have faced both personally and professionally.
Bacteria and/or yeast usually cause ear infections. Infections are painful, causing inflammation of the ear canal. Ear infections often cause a bad odor to the ears, dark debris, and scratching. But where do they come from?
The shape of the canine ear canal is often a contributing factor or the root cause of an ear infection. A dog’s ear is shaped similar to the letter “L.” The top part of the canal is vertical, running from the outer ear to the base of the head. The lower part of the canal is horizontal, running from the base of the head to the eardrum. The inner workings of the ear (ear drum, bones, nerves) are somewhat similar to that of a human. But because the outer ear canal is “L” shaped, it is easy for water, dirt, and debris to become trapped in the ear. Debris that enters at the vertical canal is drawn down the canal by gravity, and then it may become stuck, often near the eardrum. The horizontal canal is warm and dark, without much airflow, which is an ideal location for microbes to grow.
Some ear canals have structural problems that increase the risk for ear infections. Many dogs develop a stenotic ear canal, which is a medical way to say that the ear canal is narrower than it should be. Ear stenosis may occur naturally, or after many years of ear infections and scarring. This scar tissue means that the narrow ear canal cannot get adequate airflow, increasing the moisture in the ear, predisposing the dog to ear infections. Additionally, some dogs have growths or cysts in the ear. My first rescue dog, Gus, had a cyst in his ear that exuded moist material. Yeast loved this debris, so he spent many days getting his ears cleaned and treated for ear infections. Tumors in the ear are less common, but may also cause problems.
Some dogs have a lifestyle that predisposes them to ear infections. Dogs who hunt, especially in the South and in the West may develop ear infections secondary to foreign objects in the ears. Ticks, burrs, and grass awns (also called foxtails) can burrow into the ears where the dogs cannot shake or scratch them out. Dogs who swim, either for fun or for physical therapy, may also be prone if they do not get their ears cleaned after getting wet. Any activity or weather that increases water in the ear (including rain) could possibly lead to an ear infection.
Breeds such as Basset Hounds, Cocker Spaniels, Beagles, and Labrador Retrievers are prone to ear infections because they have floppy ears. The ear pinna (the outer surface of the ear) lies on top of the external opening of the ear canal, trapping air and moisture. Because these ears don’t get good airflow, the ear may stay moist, leading to ear infections. Additionally, these breeds may be prone to food allergies. Dogs with food allergies can be more prone to ear infections because the body is over-stimulated due to the protein or carbohydrate sources in the food. Common food allergies include beef and chicken. Wile E., one of our Voyce dogs, has food allergies to chicken and poultry; essentially ‘anything with feathers’. If he eats a chicken treat, he will get an ear infection in 5-7 days. Unfortunately, protein takes several weeks to be fully eliminated from the body, during which his allergies are worse (symptoms for him are itchiness, skin infections, and of course, ear infections). Some other breeds that are prone to food allergies include Boxers, Golden Retrievers, and Bulldogs (American and English).
So, what led to Joel’s ear infection? It is too early to say. Because he is a puppy, we don’t have enough history with him to know if this problem is short term, or will repeat itself over the next 15 years of his life. We will treat his ear infection with proper daily ear cleaning, as well as medicine to treat the yeast and bacteria. And we will watch him closely. His Voyce resting heart rate started increasing before he started scratching at his ears, so we were notified early that he had a problem. We will continue watching his Voyce data to see how his resting heart rate returns to normal, indicating that he is less painful, and improving.
If your dog is prone to ear infections, know you are not alone. Speak to your veterinarian about risk factors such as swimming and food allergies, to get to the root cause of the problem. And always note ear infections in your Voyce Notes, to help your veterinarian track trends that may be related to the infections. Hopefully Joel, will feel better soon. I know he and Laila are looking forward to celebrating National Pet Week, and I hope you are too!