- The vestibular system is responsible balance. It has two connected parts: the peripheral vestibular system is the inner ear and associated nerve; the central vestibular system is in the brain and spinal cord.
- We usually think of vestibular disease as either peripheral vestibular disease (PVD) or central vestibular disease (CVD).
- It occurs primarily in dogs over 8 years of age and cats of any age. We have seen vestibular disease in many other species of pets as well; rabbits are particularly prone to this disorder.
- The most common symptoms are a sudden onset of head tilt, abnormal eye movements, and loss of balance. Loss of appetite and vomiting are also common. Some pets have tremors. Many other symptoms related to the nervous system are possible.
- Loss of balance may be so mild that it is barely observable, or so severe that the patient cannot stand up. Leaning, falling, circling, and rolling might occur.
- Some pets become very anxious about their loss of balance.
- Most cases of vestibular disease are idiopathic: regardless of the amount of testing a cause cannot be determined.
- When it is not idiopathic, possible causes for PVD include: middle and/or inner ear disease; polyps in the pharynx, nose, and middle ear; abnormally low thyroid hormone levels; benign or malignant tumors; various toxicities.
- When it is not idiopathic, possible causes for CVD include: infections with viruses, bacteria, funguses, and protozoa; GME (an inflammatory disease of the central nervous system); various toxicities; cerebrovascular accident (“stroke”).
- We can usually diagnose vestibular disease with our patient history and physical exam.
- Using diagnostic tests to determine whether a pet has disease of the peripheral vestibular disease (PVD) or central vestibular system (CVD) has important implications for what can be used for treatment and for prognosis.
- Our most important tests to differentiate PVD from CVD are the general physical exam and neurologic exam.
- Additional testing that we consider on a patient-by-patient basis includes; a general blood profile, including a thyroid test; skull x-rays; and detailed exam of the ears and pharynx with our endoscopes.
- This general database might leave us with indications for tests for specific causes, such as blood tests for infections or mri for brain tumors.
- Definitive treatment for PVD or CVD is only possible when a specific cause can be determined. Since most cases are idiopathic, definitive treatment is usually not possible.
- Most pets have their most severe symptoms for the first few days, and then the symptoms gradually subside over two to three weeks.
- For the first few days, while their symptoms are most severe, many pets benefit from hospitalization for nursing care that includes comfortable close confinement, fluid therapy, and assisted feeding.
- There is no medicine that works well to help patients with idiopathic vestibular disease. Some pets are helped by treatment with the motion-sickness drug meclizine, some are helped by anti-anxiety medication.
- When a specific cause is determined: infections can be treated with antimicrobials, hypothyroidism can be treated with hormone supplementation, tumors can be treated with surgery and chemotherapy, and inflammatory disease can be treated with anti-inflammatory medication.
- Prognosis for idiopathic PVD is good. The most common course of illness we see with this problem is a sudden onset of symptoms followed by steady recovery over two to four weeks. At the end of this time, pets may have a slight head tilt but will be otherwise normal. Old dogs with idiopathic PVD are somewhat prone to having repeat episodes weeks, months or years after recovery from the previous one.
- Prognosis for idiopathic CVD is not as good as that for idiopathic PVD. A higher percentage of pets do not recover as quickly or as well, and relapse sooner when the problem is central instead of peripheral.
- The prognosis for PVD or CVD that is not idiopathic depends upon the specific cause: some infections are curable and some are not; some tumors are benign and removable, some are not; some cancers and inflammatory diseases can be managed reasonably well and some cannot.
Yarmouth Veterinary Center