Vestibular Disease in Dogs

Vestibular diseases in dogs affect the body's balance systems and can arise from peripheral (outside the central nervous system) and central (inside the central nervous system) locations. Symptoms include head tilt, incoordination, rolling or falling, and/or involuntary rhythmic eye movements (nystagmus). Salivation and vomiting may be present as a result of dizziness. Peripheral vestibular disease arises from disorders affecting the balance center in inner ear, while central vestibular disease disorders affect balance centers in the brain, primarily in the brainstem. Peripheral disease is much more common than central disease. Causes of peripheral vestibular disease include inner and middle ear infections, trauma, tumors and polyps, nerve damage from under-active thyroid gland or aminoglycoside antibiotics, and congenital (from birth) and idiopathic (unknown cause) geriatric syndromes. Causes of central disease include cancer, loss of blood flow (vascular infarct), trauma or bleeding, infections, and inflammatory disease.

Common name: Canine vestibular disease (vestibular disease in dogs)
Scientific name: Canine vestibular disease, Geriatric vestibular disease

Diagnosis

Signalment
Signs of congenital vestibular disease in dogs can be seen in purebred dogs as early as birth, but generally before 3 months of age. Affected breeds include German shepherd, Doberman pinscher, Akita, English cocker spaniel, beagle, smooth fox Terrier, and Tibetan terrier. Geriatric canine vestibular disease is associated with old age, with the mean age being 12.5 years, and is often mistaken for a stroke. Other vestibular disorders are not age-related.

Incidence/prevalence
Peripheral vestibular disease is much more common than central vestibular disease.

Geographic distribution
There is no known geographic predilection for this disease.

Clinical signs primary (most to least frequent, scientific term, synonyms)
Head tilt toward the side of the lesion, ataxia (stumbling, staggering, incoordination) falling or rolling toward the side of the lesion Nystagmus (involuntary rhythmic eye movements).

Clinical signs secondary (most to least frequent, scientific term, synonyms)
Vomiting, drooling, strabismus (deviation of the eyeball within the socket), unequal pupils, inability to blink.

Causes (scientific, common term)
Congenital (genetic predisposition), infections, trauma, drugs, tumors and polyps, hypothyroidism, idiopathic (unknown cause, seen in geriatric dogs), inflammatory diseases of the brain, vascular infarct (loss of blood flow).

Organ system affected (most to least affected)
Middle and inner ear, brain, cranial nerves.

Diagnostic tests
Radiographs, culture and sensitivity, cytology, cerebral spinal fluid analysis, CT and MRI scans.

Differential Diagnosis
Other neurological disorders that cause an abnormal gait, stroke, congenital nystagmus, external ear infections.

Differential Diagnosis
Other neurological disorders that cause an abnormal gait, stroke, congenital nystagmus, external ear infections.

Overview

Vestibular diseases affect the body's balance systems and can arise from peripheral (outside the central nervous system) and central (inside the central nervous system) locations. Symptoms include head tilt, incoordination, rolling or falling, and/or involuntary rhythmic eye movements (nystagmus). Salivation and vomiting may be present as a result of dizziness. Peripheral vestibular disease arises from disorders affecting the balance center in inner ear, while central vestibular disease disorders affect balance centers in the brain, primarily in the brainstem. Peripheral disease is much more common than central disease. Causes of peripheral vestibular disease include inner and middle ear infections, trauma, tumors and polyps, nerve damage from under-active thyroid gland or aminoglycoside antibiotics, and congenital (from birth) and idiopathic (unknown cause) geriatric syndromes. Causes of central disease include cancer, loss of blood flow (vascular infarct), trauma or bleeding, infections, and inflammatory disease.

Treatment

Home Care
Home treatment consists mainly of nursing care and careful confinement. Dizziness may prevent dogs from walking well if at all. Food and water should be nearby, and may need to be offered by hand. Helping a dog to eliminate by supporting the body may be necessary.

Professional Care
Diagnosis of the cause is key to treatment. Physical examination, including a neurological exam, will determine if central or peripheral disease of the vestibular system is present. If peripheral disease is found, otoscopic (deep ear examination) examination and sometimes radiographs, blood tests, cultures and cytology may be performed to differentiate among possible causes. Antibiotics are used to treat ear infections. Nausea and vomiting caused by dizziness can be helped with motion sickness medication. Congenital and geriatric causes do not have specific treatment, and supportive care is beneficial. Surgical biopsy is needed to identify tumors and polyps. Cerebral spinal fluid taps, MRI, CT scan and blood tests are all useful in determining causes of central vestibular diseases.

Action
A veterinarian is necessary to diagnose vestibular disease in dogs and differentiate among the causes, as well as initiate the appropriate treatment. Progress exams and repeat blood work are indicated to monitor response to treatment.

Outcome
Puppies often adapt to congenital causes of vestibular disease, and appear less affected as they mature. Geriatric vestibular disease usually resolves in 1-2 weeks, although a head tilt may persist. Most middle/inner ear infection requires at least 3 weeks of antibiotics, but clinical signs often resolve sooner. Hypothyroidism carries a good prognosis with thyroid hormone supplementation. Prompt discontinuation of drugs that are toxic to the vestibular system often results in complete return to function, but there may be residual deafness. Removal of polyps often results in cure, but cancers generally have a poorer prognosis. The causes of central disease usually carry a poor prognosis, as it indicates potential damage to the brainstem, which can have devastating consequences. Any infection that can be identified should be treated. Inflammatory causes may be initially treatable, but are often progressive and tend to stop responding to medication.

References/Additional Readings

Nelson, Richard W. & Couto, C. Guillermo. Head Tilt In: Manual of Small Animal

Internal Medicine, St. Louis: Mosby Inc., 1999; 599-603.

Oliver, John E Jr., & Lorenz, Michael D. In Handbook of Veterinary Neurologic Diagnosis, Philadelphia, W. B. Saunders Company, 1983; 223-232.

Author
Janice Fenichel, DVM

Editor
Sharon Gwaltney-Brant DVM, PhD
DABVT, DABT