Microbiology in canine otitis externa

Introduction Otitis is a frequent problem in dogs – in many cases we deal with a recurrent problem. Looking at the etiology we have to take into account bacterial infections, yeasts (Malassezia spp.), parasites (Otodectes cynotis as well as Demodex species) and foreign bodies. Less often we deal with neoplasia, allergies (especially food intolerance), autoimmune diseases or endocrinopathies that induce otitis, most commonly complicated by bacteria or yeasts. In contrast, cats rarely suffer from otitis externa. Most common causes in cats are parasites or allergic diseases including atopy and food intolerance. Bacteriological and mycological examination is needed instead of routine application of antibiotics since a large percentage is complicated by yeast. An underlying cause always has to be considered in order to obtain a successful treatment.