Balancing Act
My dog was diagnosed with Geriatric Vestibular Syndrome. What is it?
Geriatric Vestibular Syndrome (GVS) is often referred to as “old dog vestibular syndrome.” It is a sudden and non-progressive disturbance of balance. GVS is almost exclusively a condition of older dogs. This disorder stems from issues affecting the dog’s vestibular system within the brain as well as the middle and inner ear.
Like humans, the vestibular system is the neurologic equipment responsible for perceiving the body’s orientation relative to the earth. This determines if you are upside down, standing up straight, falling and so forth, and in turn informs the eyes, arms and legs how they should move accordingly.
The vestibular system allows us and our dogs to walk, even run, on uneven ground without falling, helps us know when we need to right ourselves, and allows our eyes to follow moving objects without becoming dizzy. In short, the vestibular system consists of the structures of the middle ear, the nerves that carry their message to the brain and central nervous system, and the brain /central nervous system itself.
If we are asleep and start to fall, the vestibular system would wake us up. This is why rolling an anesthetized dog from side to side is used to speed up recovery from anesthesia.
GVS is any abnormal function of the middle or inner ear that causes a sudden loss of balance and coordination, among other symptoms. Since the inner ear is part of the middle ear, any disease that affects the middle ear or specifically targets the middle ear may cause vestibular disease. In many cases, the cause of GVS is termed “idiopathic,” or unknown.
Is Geriatric Vestibular Syndrome similar to vertigo?
Like vertigo, which causes dizziness in humans, vestibular disease in dogs is caused by a dysfunction of the inner ear. The symptoms of vestibular disease in dogs are similar to the symptoms of vertigo in humans.
What are the signs of Geriatric Vestibular Syndrome?
The signs of GVS appear suddenly and typically do not progress or worsen over time. Your dog will show the strongest symptoms of the disease within the first 48 hours and will slowly improve over two to three weeks.
The most common symptoms of GVS in dogs are ataxia, head tilt, nausea and nystagmus.
Ataxia is a lack of coordination without weakness. The dog will be stumbling and staggering around. The legs actually do function, but the dizziness the dog experiences when trying to stand make it difficult for them to stay upright.
The head will be tilted to one side. Most dogs lean or fall in the direction that their head is tilted.
Some dogs are quite nauseated. The sensation is much like riding non-stop on a merry-go-round. They may drool or vomit and be unwilling to eat or drink anything.
Nystagmus is the term for the back-and-forth movement of the eyes. The movements will be slower in one direction. This is the side where the neurologic problem is likely to be.
Most clients are distraught when they bring their dog in. While the patient certainly looks abnormal, it is always a relief to see this combination of symptoms, as the prognosis for recovery from GVS is generally very good.
Is it possible that my dog had a stroke?
Vestibular signs are commonly, and usually incorrectly, referred to as a stroke. An ischemic stroke occurs when the blood supply to part of the brain is blocked or reduced. This prevents the brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes.
Another type of stroke is a hemorrhagic stroke. It occurs when a blood vessel in the brain leaks or bursts and causes bleeding in the brain. The blood increases pressure on brain cells and damages them. Both kinds of strokes are medical emergencies.
While an accident with a blood vessel is a possible cause of vestibular signs, it is a rare cause. Diseases of the blood vessels, while common in people, are unusual in dogs.
What causes Geriatric Vestibular Syndrome?
The most common form of GVS is idiopathic, meaning the cause is unknown. In rare cases, GVS may be the result of a tumor, an infection (especially Rocky Mountain Spotted Fever), a middle-ear infection or damage to a blood vessel in the brain.
GVS begins suddenly and resolves suddenly. Usually, improvement is noticeable in 72 hours, and the dog is normal in seven to 14 days, although occasionally a head tilt will persist. When a case of GVS begins, it may be a good idea to wait a few days to see if improvement occurs before doing diagnostics beyond a routine blood and urine database.
Treatment of idiopathic vestibular disease generally involves controlling the nausea and motion sickness while the condition runs its relatively short course. Cases of GVS that are not resolving may need advanced diagnostics such as an MRI or CT scan to get detailed images of the brain.
If your dog has a middle-ear infection, cleaning of the external ear can lead to a flare-up of vestibular symptoms. This is often unavoidable in chronic ear infections, as there is no way to know if an external ear infection extends into the middle ear.
Treating a middle-ear infection can be difficult. A culture of the middle ear may be necessary, and oral antibiotics are needed for six to eight weeks to clear the infection from the tiny bones of the middle ear. Surgery may be needed to flush out the infection.
What is the treatment for Geriatric Vestibular Syndrome?
If the cause of the dog’s vestibular issues is known (infection or tumor), then treatment will be directed to that condition. If the vestibular disease is idiopathic, then treatment is tailored to the symptoms displayed. Anti-nausea or anti-anxiety medication may be prescribed. Antibiotics are used in cases suspected of having middle- or inner-ear infections. Although corticosteroids (prednisone) have been prescribed in the past, there is little scientific evidence that their use is beneficial for this condition.
Supportive treatment includes close monitoring, especially if the dog has trouble walking. They may need to be carried or lifted and supported with a sling to relieve themselves outside. If your dog does not get up enough, such issues such as bed sores and urine scald may develop. Change your dog’s position from side to side every four to six hours if they are not moving themselves.
An unsteady dog may sustain an injury from a fall. Since the main issue with GVS is balance, it is helpful to provide good footing, keep the floor clear of obstacles, and block off the stairs to keep your dog safe.
Check your dog’s skin closely and bathe them regularly if they soil themselves. Wee Wee Pads or chucks pads from a human hospital can be used as bedding, as they are soft, sanitary and easily changed.
The nystagmus makes it difficult for dogs with GVS to focus, so they may need to be hand-fed and have the water brought to them for drinking. Eating and drinking can be a problem if the dog is having trouble locating the food and water dishes. Dogs that are so nauseated or disoriented may need to be hospitalized temporarily at your veterinarian for intravenous fluids.
What is the prognosis for dogs with Geriatric Vestibular Syndrome?
The good news is that the physical signs resolve quickly and usually start to improve within 48 hours. Over the next week, your dog should be much steadier walking, and the eye movements and head tilt should start to go away. Most dogs are normal within two weeks after the initial onset of signs. Sometimes there is a minor head tilt that will persist even after the dog seems back to normal. Dogs who have had an episode of GVS may be prone to recurrence.