The ear is divided into three parts. An infection of this outer ear is termed otitis externa. An infection of the middle ear is called otitis media. These structures convert sound impulses from the middle ear into electrical impulses that then travel along the auditory nerve to the brain. These structures are also responsible for maintaining the overall balance of the dog.
Infection here is termed otitis interna.
The ear canal is structured in such a way that it commonly is affected by infectious processes. In our breed, it is about two inches in total length with an upper diameter similar to that of a pencil. It begins at the outer ear and travels downward. Along the way, it changes its direction and becomes horizontal. This two-directional anatomy serves to protect the eardrum from injury, but also predisposes to wax, water and dirt collection at its base.