Ear infections are common in every breed, though those with narrow or hairy ear canals, or predisposed to allergies, are the most affected. Such breeds include Cavoodles, Poodles, French Bulldogs, Staffordshire Bull Terriers, Bull Terriers, Beagles, Schnauzers, West Highland White Terriers, Labradors, Cocker Spaniels, and Golden Retrievers. Quite an exhaustive list!
Once a dog has ear infections it is almost always a recurring issue. Ear infections are caused by factors that change the environment in the ear and are not contagious. Anything that creates a warm, wet environment can cause the organisms that normally line the ear canal to grow out of control. These factors include swimming or bathing, inflammation from allergies, narrow/hairy ear canals preventing air from circulating, and floppy ears.
Ear infections are generally caused by two organisms – bacteria and yeast. In general, dark brown waxy ear discharges are generally associated with yeast-based infections, or yeast/bacteria mixed infections, and yellow ear discharges (looking more like pus) are associated with a particular type of bacterial infection. When diagnosing an ear infection we take a swab of the ear canal to assess under a microscope which organism is present as it alters the type of ear medication we treat it with.
Ear mites are a relatively common cause of ear infection in puppies, though are almost unheard of in adult dogs. Many new generation flea & tick preventatives such as Simparica, Nexgard, and Bravecto kill ear mites, so topical ear medications are rarely required unless there is also a bacterial or yeast component to the infection.
Dr Caroline Wood