Vestibular Disease

Peripheral vestibular disease is a neurological disorder affecting animals’ balance and special awareness. The peripheral vestibular nerves control eye movement, head position and balance. Accordingly, these functions can be affected by problems with those nerves. The symptoms can also be caused by problems in the brain stem, but this is much less common. Idiopathic simply means the cause is unknown.

Clinical Signs
The most obvious sign of vestibular disease in dogs and cats is a head tilt. Head tilting occurs when the disease obstructs normal feedback information from the brain that determines the animals’ special orientation. This disturbance is almost always associated with a disturbance in gait, commonly termed ataxia. Severely affected animals may circle or call toward the side of the head tilt or even roll to the affected side. The eyes will often jerk or sometimes circle uncontrollable (termed nystagmus). Chronically affected animals often no longer have nystagmus and some other symptoms may not be prominent. Vomiting may also be seen, presumable due to vertigo.

Differential Diagnosis
By definition, idiopathic vestibular disease is diagnosed when all efforts to determine a cause have been unproductive. In developing a differential diagnosis (meaning a list of possible causes), consideration is given to whether the problem could be with the peripheral or central (brain stem) vestibular involvement. Sometimes the peripheral nerves can be affected by something as basic as an ear infection; however, there are various other causes as well. A diagnosis of idiopathic vestibular disease is confirmed when the symptoms stop spontaneously.

Treatment and Prognosis
Treatment may not be necessary in dogs and cats with an acute (sudden) onset of idiopathic vestibular disease. Most affected animals recover without treatment, although steroids, antibiotics, and topical ear medications are commonly given. Although the cause of the disease is unknown, the recovery in these animals is almost always good. The nystagmus should resolve within 3 days, and the following several weeks should show good recovery of the other symptoms. Some residual head tilt may persist, although most of the other clinical signs will usually resolve. Good communication between the owner and veterinarian is very important. If the pet does not improve steadily, or other signs develop, additional evaluation is necessary.