Otitis media in dogs refers to middle ear inflammation. The middle ear has various structures that are responsible for maintaining the body’s balance, in addition to the sense of hearing. Otitis media is usually a result of inflammatory conditions spreading from the external ear, but it may occur due to a puncturing wound in the eardrum through which foreign bodies may enter the middle ear. An infection in the blood (sepsis) may spread to the middle ear too, but it is not very common. Middle ear inflammation may spread to the inner ear, resulting in otitis interna, which may render the dog deaf.
The typical symptoms of otitis media in dogs resemble those of external ear inflammation. The dog may express its discomfort by head shaking and head rotation in the direction of the affected ear. It may repeatedly rub that ear on the ground. Otitis media is a painful condition accompanied by a draining discharge from the affected ear. Frequent recurrence of otitis externa may be an indication of an underlying inflammation of the middle ear.
Facial paralysis accompanied by drooping eyes, constricted pupils and sunken eyeballs may occur due to the involvement of the facial nerve as well as the sympathetic nerve that pass through the dog’s middle ear. The third eyelid may be protruding. These symptoms are restricted to the affected side of the head.
Otitis interna in the dog may affect its balance and coordination; hence lack of coordination is considered a definitive symptom of inner ear inflammation. The dog may find it difficult to get up or walk because of this symptom. The dog’s head may be tilted to the side of the inflamed ear. Rhythmic to and fro eye movements, known as nystagmus, another typical symptom of this condition, may occur too.
Diagnosis of otitis media is based on the medical history of the dog, symptoms displayed and a physical examination conducted by the veterinarian. The dog may have a history of chronic external ear inflammation, a penetrative injury of the eardrum or its rupture. An ear discharge filled with pus or a fluid collection in the middle ear indicates otitis media. X-rays may show a hardening of the round bone located at the back of the ear (the tympanic bulla) or overgrowth of fibrous tissue on it. CT scan may also help in diagnosing otitis media in dogs.
Diagnosis of otitis interna is also by the symptoms, especially the lack of balance experienced by dogs with this condition. An otoscopic examination and x-rays of the ear as well as that of the tympanic bulla may help confirm the diagnosis.
If the dog has either otitis media or otitis interna, the veterinarian may treat it with antibiotic therapy until the issues are completely resolved. Damage to the vestibular apparatus that control the body’s balance and to the cochlea or the hearing organ is a definite possibility if these inflammatory conditions are not controlled as early as possible. Long term treatment often extending from 3 weeks to 6 weeks may be necessary. The antibiotics may be administered either orally or as injections, along with anti-inflammatory medications to reduce the swelling and keepi t from reaching the nerves in the vicinity. If the eardrum has tiny perforations, they may heal in a few weeks, but if it is ruptured, the middle ear is gently cleaned.
If the there is no inflammation in the external ear canal, but the middle ear is severely inflamed with the eardrum bulging outwards, the veterinarian may relieve the extra pressure in the middle ear by making a small perforation in the eardrum. This not only relieves pain, but also facilitates the draining of fluid accumulated in the middle ear. The discharge may be cultured to detect infectious agents that may be responsible for the inflammation and to determine the suitable medication to treat the infection. However, since this treatment may potentially cause hearing loss, other options may be considered first. If long term antibiotic therapy is not having the desired effect, surgical intervention may be necessary to resolve otitis media.
If the eardrum is intact, oral administration of antibiotics may be sufficient to treat otitis media, but if it is complicated by either a ruptured eardrum or a longstanding inner ear inflammation, the prognosis is not very good. If the nerves are affected, the symptoms typical of neurologic involvement may remain even after the successful resolution of otitis media. Otitis interna usually gets resolved by long term antibiotic treatment but the symptoms such as deafness, head tilt, loss of blinking ability, drooping of lips etc., may remain. The dog may continue to be disoriented and may require continued supportive care and plenty of time to adjust to the persistent neurologic symptoms.
Ear inflammations should be treated as soon as possible to avoid permanent disabilities and symptoms. The dogs should be observed carefully for indications of middle and inner ear inflammation such as head tilting, alterations in movement and balance or any discharge from the ears. The earlier the treatment is initiated, the better the outcome.