Stroke or Vestibular Disease?
Vestibular Syndrome, variously referred to as Peripheral Vestibular Syndrome, Idiopathic Vestibular Syndrome (meaning it occurs for no known reason) and Geriatric Vestibular Syndrome (more common in older dogs but can occur in middle aged dogs) are all names for the same condition now commonly referred to as Vestibular Syndrome.
The vestibular system senses the position of the head and body in space, in relation to gravity and movement. This helps the animal maintain balance and coordinate eye movements with movement of the head.
The receptors for the vestibular system are located in the inner ear, adjacent to the hearing receptors. Vestibular information is processed in the lower portion of the brain in the brainstem and cerebellum, therefore a problem in the inner ear or one in the brain can affect the vestibular system.
The phrase "vestibular disease" is a general term referring to any abnormality of the vestibular system, although some people use this term to mean idiopathic vestibular disease (see below).
This syndrome is not a life threatening condition, nor should it even be called "old dog vestibular syndrome" as is sometimes the case because young dogs have also contracted it. However, in most cases it will be older dogs who have this condition.
This condition is sometimes misdiagnosed since the dog may display many of the same symptoms that are associated with a brain tumor or a stroke victim. Unfortunately, affected dogs who would have recovered have been euthanized because the condition appears so severe.
Time is a major factor in vestibular syndrome. Recovery time depends on the afflicted dog. Eventually the animal teaches itself to compensate for its changed physical behaviour.
Rest and quiet are required during this recovery time, and it’s important to keep the dog in a well lighted room. If possible, avoid carrying the dog or if this is unavoidable, lift the dog slowly and smoothly and hold the pads of it’s feet while airborne. Lifting and moving it through the air disrupts the dog’s sense of orientation.
Keeping the dog’s feet firmly on the ground with it’s eyes on the horizon helps regain it’s balance.
It is important to note that there are no warning signs, which may lead to the conclusion that it is a stroke. Fortunately most dogs will be spared this affliction. However, if your dog does contract this disease, it is comforting to know that it is not fatal and recovery is merely a matter of patience and tender loving care.
There is sudden loss of balance with many dogs unable to even stand up. Dogs may be nauseous from the "sea sickness" effect of vestibular disease. are often distressed, and their owners fear they will never recover.
Clinical Signs of Vestibular Disease Include:
As long as they are nursed through this condition almost all dogs will recover. In some cases of vestibular disease, there is a sudden onset of severe signs. This may initially be confused with a seizure.
A wide-based stance and swaying of the head and trunk characterize ataxia. The patient may tend to lean and fall to one side. In severe cases, the animal may continuously roll to one side.
It usually lasts between a couple of days and three weeks. A few dogs have residual signs beyond this time, such as a head tilt. This disease normally affects dogs that seem normal up until the signs appear. Then there is sudden loss of balance with many dogs unable to even stand up.
Diagnosis: Identification of vestibular dysfunction is based on recognition of the specific signs. The veterinarian diagnoses the cause of the disorder with a medical history and examination.
In some cases, further diagnostic tests, such as x-rays, computed tomography, or magnetic resonance imaging is necessary.
Ear infection: Infection of the middle/inner ear is a common cause of vestibular disease in the dog. Most cases can be diagnosed by a thorough examination of the ear with an otoscope. A serious inner/middle ear infection—which can occur without the customary smelly ear—has the same severe and frightening symptoms. An infection can usually be cured with antibiotics and the dogs have a complete recovery.
Drugs that might be used to treat old dog vestibular syndrome include Cholodin Tabs and Winstrol V. As always, check with your vet.
Ear culture, X-rays, computed tomography or magnetic resonance imaging is sometimes necessary. If bacteria cause the infection, treatment consists of appropriate antibiotics.
Hypothyroidism: Hypothyroidism can cause vestibular dysfunction in dogs. Signs may develop suddenly or over time. Diagnosis is based on laboratory evaluation of thyroid function and response to thyroid supplementation. Vestibular dysfunction typically resolves within 2 months of treatment.
Toxicity: Medications placed in the ear are the most common cause of vestibular toxicity; although some orally administered drugs can also be a problem, especially at high doses. Ear drops or other substances should never be placed in a dog's ear except on the specific recommendation of a veterinarian.
Cancer: Tumors in the inner ear or brain can cause vestibular problems. Older animals are more commonly affected and there may be pain on opening the mouth. Diagnosis is based on x-rays, CT, MRI, and/or biopsy.
Encephalitis: Inflammation of the brain (encephalitis) can cause vestibular dysfunction. Causes include infections, such as distemper virus, and non-infectious causes. Diagnosis often requires analysis of spinal fluid. Some types of infection can be specifically treated with medications.
Idiopathic Vestibular Syndrome: Idiopathic just means "happens for no known cause". For reasons unknown, dogs can suddenly develop vestibular disease. Some believe certain types of antibiotics such as streptomycin and gentomicin are thought to be the cause.
Older dogs (mean age 12.5 years) are primarily affected. There is a sudden onset of ataxia (a neurological sign and symptom consisting of gross incoordination of muscle movements which can be severe), head tilt, nystagmus (an involuntary rhythmic shaking or wobbling of the eyes and occasionally vomiting. The cause of this syndrome is unknown.
Diagnosis is based on the signs and excluding other causes of vestibular dysfunction. Affected dogs improve spontaneously within 2 weeks, although there may be a mild, persistent head tilt.
Nursing care is important during recovery. Even when dogs do not recover fully from peripheral vestibular syndrome they normally have a good life. They adjust to residual problems like head tilts and do not seem all that bothered by them. If progress towards recovery is not evident, then the other disorders mentioned above need to be considered.
Peripheral vestibular disease can be confused with anything that will cause cerebella damage or inner ear disease. Inner ear infections are probably the most common cause of similar symptoms and if recovery does not progress satisfactorily it is a good idea to do whatever testing seems necessary to rule out inner ear problems, such as ear examination and X-rays. Cancer affecting the cerebellum, the peripheral nerves to the cerebellum or the inner ear can cause similar signs.
In Golden Retrievers, lymphoma is a common cancer problem that can cause CNS signs. Trauma is a possible problem that could be confused with peripheral vestibular syndrome if brain damage occurs. Granulometous meningoencephalitis (GME). Infarcts (blood clotting leading to lack of circulation in part of the brain) occur in some dogs.
If the damage to the brain is minimal then recovery may occur quickly. If the damage is severe, recovery may not occur at all. I do not know the incidence of infarcts affecting the brain in dogs but I think it is pretty low.
see also: Stroke in Dog