Ear infections are one of the most commonly diagnosed conditions in dogs. Below is a list of underlying causes of external ear infections in dogs:
Allergies: Environmental (atopy) and food allergies can cause inflammation of the external ear. Allergies are the most common cause of external ear infections in dogs. The ears develop a bacterial and/or yeast infection secondary to the allergic inflammation of the external ear. The only sign of atopy or a food allergy could be an ear infection. However, allergies often cause skin infections on more then one area of the body, such as the paws and underside of the belly.
Foreign bodies: They can cause irritation and a secondary infection. The most common foreign bodies in dogs are grass awns and foxtails. They are only present in certain parts of the country, such asCalifornia, and are primarily problematic during Spring and Summer.
Certain breeds: Cocker Spaniels and other dogs with large floppy ears that create a warm, dark, moist environment are prone to chronic external ear infections that are sometimes impossible to resolve. Some dogs, such as Standard Poodles, can have thick hair down in the ear canals that create a warm, dark, moist environment for infections to occur. But it is important to know that many dogs with hairy ears never develop ear infections.
Other less common causes: Dogs that swim can get external ear infections from the excessive moisture in the ear canal. Ear mites rarely cause ear infections in dogs. Ear cleaning solutions can cause irritation of the external ear and secondary infections. Hypothyroidism can be the underlying cause of an external ear infection in dogs.