What is the vestibular system?
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.
What is vestibular disease?
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.
What are the clinical signs of vestibular disease?
Most dogs present with a sudden loss of balance, disorientation, head tilt, and irregular, jerking eye movements called nystagmus. Many dogs will become reluctant to stand or walk. Most dogs lean or fall in the direction that their head is tilted.
What causes vestibular disease?
Causes of vestibular disease include middle ear or inner ear infections; drugs that are toxic to the ear; trauma or injury; tumors; and hypothyroidism. When no specific cause is found, the condition is called idiopathic vestibular syndrome. Idiopathic cases are distinguished by the sudden onset of clinical signs and the subsequent, rapid improvement with little, if any, medical intervention.
How is vestibular disease diagnosed?
Diagnosis is based on medical history, clinical signs, and the results of blood and urine tests. An ear exam with an otoscope will be done to assess the external ear canals and ear drums. A ruptured or bulging ear drum can be a sign of a middle and inner ear infection.
In some cases, other diagnostic testing might include blood pressure measurement or X-rays (radiographs) of the head to assess the skull and the tympanic bullae. Occasionally, magnetic resonance imaging (MRI) or computed tomography (CT) scans will be performed to look for tumors or other brain abnormalities. Brainstem auditory evoked response (BAER) testing may also be performed in some patients to assess hearing.
The criteria for diagnosing canine idiopathic vestibular syndrome are:
- older dog
- sudden onset of peripheral vestibular signs
- no detectable cause (i.e., no signs of external or middle ear infection, ototoxicity, head trauma, hypothyroidism, infectious disease, etc.)
- signs resolve on their own over several weeks
How is vestibular disease treated?
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 dog can eat and walk on its own. If the dog 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 may be beneficial. Antibiotics may be used in cases suspected of having middle or inner ear infections. Although corticosteroids have been used in the past, there is little scientific evidence to support their use in this condition, and they are generally not recommended.
In less severe cases, nursing care at home will likely be sufficient. This care includes helping your dog get up, walk, and go to the bathroom. The dog may also require assistance with eating, drinking, and keeping themselves clean in case of accidents.
What is the prognosis for a dog diagnosed with vestibular disease?
The clinical signs associated with vestibular disease are often most severe during the first 24 to 48 hours. Many pets begin to improve within 72 hours. The head tilt and stumbling often improves over a 7 to 10-day period. Most patients are completely recovered within 2 to 3 weeks, although some will have residual symptoms, such as a head tilt or mild "wobbling" for life. Dogs who have had an episode may be prone to recurrence.
If the patient fails to improve or worsens, then a more severe underlying disorder should be suspected, and advanced diagnostic testing should be pursued. A referral to a veterinary neurologist may be advised.
