The vestibular system is responsible for maintaining normal balance. The vestibular system has central components located in the brain, and peripheral components located in the inner and middle ear.
Vestibular disease refers to a sudden, non-progressive disturbance of balance. Most dogs present with the sudden onset of loss of balance, disorientation, head tilt and irregular jerking eye movements called nystagmus. Many dogs will become reluctant to stand or walk. Most dogs will lean or fall in the direction of their head tilt.
Causes of peripheral vestibular disease include:
- Middle or inner ear infections
- Drugs that are toxic to the ear
- Trauma or injury
- Idiopathic vestibular syndrome.
Causes of central vestibular disease include:
- Inflammatory disease (infectious and immune mediated)
- Neurodegenerative diseases
- Toxins (i.e. metronidazole)
Metabolic causes are often ruled out by medical history, clinical signs, blood and urine tests. Magnetic resonance imaging (MRI) or computed tomography (CT) scans will be recommended to look for structural changes with the brain. A spinal fluid analysis may be recommended to screen for inflammatory diseases.
Treatment is directed at the underlying cause, if one can be identified. In severe cases, supportive therapy such as intravenous fluids and hospitalization may be required until the pet can eat and walk on its own. If the pet is seriously disoriented or ataxic (stumbling, unable to stand or walk), it may be given sedatives to help it relax. Drugs that help combat nausea or motion sickness such as meclizine or Cerenia may be beneficial. Antibiotics may be used in cases suspected of having middle or inner ear infections.
The prognosis is largely dependent on the underlying cause.