 | This article needs more reliable medical references for verification or relies too heavily on primary sources. (November 2018) |  |
Otitis externa is an inflammation of the outer ear and ear canal. Animals are commonly prone to ear infection, and this is one of the most common manifestations of allergy in dogs. In dogs, those breeds with floppy ears are more prone, since air flow is limited and a warm, moist environment built up, which is conducive to infection. The external ear in animals is longer and deeper than in humans, which makes it easier for infection or wax to build up or be hard to remove. Complete ear canal inspection requires the use of an otoscope by a veterinarian.
Infections are usually secondary to inflammation or to improper grooming techniques. Infections can be caused by both bacterial and fungal origin, as well as small organisms such as ear mites. Malassezia pachydermatis is a common fungal agent for ear infections in dogs. Staphylococcus intermedius is the most common bacterial infection. A more serious ear infection, with pus in the ear, may be caused by Pseudomonas aeruginosa.