Inflammation of the middle ear structures (otitis media) is usually due to extension of infection from the external ear canal or to penetration of the eardrum by a foreign object. Spread of infection by means of blood to these areas is possible but rare. The signs of otitis media are similar to those of otitis externa (see Ear Disorders of Horses: Otitis Externa in Horses).
Inflammation of the middle ear may lead to inflammation of the inner ear structures (otitis interna). This can in turn lead to loss of balance and deafness (see Ear Disorders of Dogs: Otitis Media and Interna in Dogs).
Last full review/revision July 2011 by T. Mark Neer, DVM, DACVIM; Michele R. Rosenbaum, VMD, DACVD; Patricia D. White, DVM, MS, DACVD