Syndrome is dizziness caused by a failure of the vestibular system –
the organs involved with the sense of balance. The vestibular system
consists of part of the inner
ear called the semi-circular canals and regions of the brain that
process the sense of balance. Usually only one side stops working, so
the dog loses its sense of which way up it should be.
The dog appears dizzy or
drunk and if it can stand it will tend to walk in circles and fall over
to one side.
Many dogs are unable to stand and will lie on one side only. The eyes
to flick from side to side, moving slowly in one direction and flicking
back. They will often pant and may vomit. If able to stand, the head
often be tilted to one side.
Vestibular syndrome can be
caused by an infection in the middle ear that spreads to affect the
inner ear. In these cases, there is often pain in one of the ears and
head shaking may have
been present for some time previously.
The cause is unknown In most cases of vestibular
syndrome. This is
known as Idiopathic Vestibular Syndrome. This occurs in older dogs and
is often referred to as a “stroke” to help people understand what has
happened to their dog, although the cause is not the same as a stroke
in humans – there is no blood clot or bleed to cause it. Factors that
seem to be related to incidence of this problem include general
anaesthetics, heart disease, poor circulation and very hot weather.
These are all factors that can affect the blood flow in the brain and
all indications are that the cause is a disruption of the blood flow to
the brain. There are similarities with Meniere’s Disease in humans. It
possible for a blow to the head to cause vestibular syndrome, but this
Provided that only the
vestibular system is affected, the prognosis is usually very good for a
full recovery. However, in some cases, other parts of the brain can be
affected at the same time. Generally, if the dog is able to recognise
its owner and is at least partly aware of what is going on, it will
If an underlying cause is
suspected, then treatment must be given for that. A middle ear
infection will require antibiotics and anti-inflammatory drugs. No
drugs have definitely been proven to help dogs recover from Idiopathic
Vestibular Syndrome. An injection of steroid soon after it occurs has
been proven to help many brain injuries, so it is possible this will
speed recovery. Otherwise drugs that help to improve
the blood flow to the brain are often given, such as Vivitonin or
particularly if the dog has other evidence of poor circulation.
Treatment is aimed at making
the dog more comfortable. Drugs may be given to prevent vomiting
and if the dog is unable to settle, tranquillisers will help. In the
early stages it is best for the dog to rest quietly lying down. They
may require help taking
food and drink until they regain some stability. Once they start to
better in themselves, particularly after the eyes have stopped
flickering, it is useful for them to try and get around. When they
first start moving around again, they will be unstable and fall often.
To help them through this
phase it is best to protect them from falling on hard floors/objects
to loop a towel under the body when they walk to help them. They should
have access to stairs without help. Lifting them off the floor at this
is often distressing – they learn to use the floor as a reference for
balance. Walking around at this stage will speed their recovery – it is
a learning process, so practice helps.
Most dogs will make a
reasonable recovery within 2 weeks of the problem starting. In many
cases, it seems that
the damage does not repair, but rather the brain learns to cope with
change in the sense of balance. The dog is often left with a head tilt,
worse than when the problem first started, but will be able to get
normally. Many people contemplate euthanasia when a vestibular attack
However, if the dog is otherwise in good health and aware of the people
them, the prognosis is good, although it takes a little time. If,
the dog is already suffering with poor health or seems to have suffered
to other parts of the brain also, euthansia may be the kindest option.
Canine Vestibular Disease
Vestibular Disease in Cats and Dogs
Canine Vestibular Disease
One day our 15 year old dog
became disoriented, unbalanced and appeared to be confused. He was
leaning toward one side, shaking his head, going around in circles,
etc. We thought he may have had a stroke and took him to the emergency
animal clinic. Instead of stroke it turned out he was suffering from
Canine Vestibular Disease—also known as “old dog vestibular syndrome.”
Vestibular means a problem with the connections between inner/middle
ear and brain causing ataxia. Dogs with ataxia stand with their limbs
braced, they walk with difficulty and have a “drunk” type of motion
they have lost their sense of balance. When the vestibular nerve, which
travels from the inner ear to the brain, malfunctions. It disrupts the
animal’s sense of balance and orientation.
It is important to find out where the vestibular abnormality is
located. The disturbance can be peripheral, meaning it is located
outside the brain, or central, located inside the brain. The
distinction between the two
is subtle and is best diagnosed by a veterinary neurologist. The
peripheral disturbance is the most common and least serious.
It has been suggested that there is a correlation between old dog
vestibular syndrome and hypothyroidism so blood work should be done to
rule out this problem.
The ears should be thoroughly examined because the same symptoms can
result from a severe ear mite infection. Also certain types of
antibiotics such as streptomycin and gentomicin can cause vestibular
This syndrome is not a life threatening condition, nor should it even
be called old dog vestibular syndrome because young dogs have also
contracted it. However, in most cases old dogs are seen by
veterinarians with this condition more often.
Time is a major factor in old dog vestibular syndrome. Recovery time
depends on the afflicted dog. Eventually the animal teaches itself to
compensate and overcome old dog vestibular. 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
lift the dog slowly and smoothly and hold the pads of it’s feet while
Lifting and moving it through the air disrupts the dog’s sense of
Keeping the dog’s feet firmly on the ground with it’s eyes on the
helps regain it’s balance. This condition is sometimes misdiagnosed and
dogs who could have recovered have been euthanized because the
appears so severe. It is important to note that there are no warning
which may lead to the conclusion that it is a stroke. Fortunately most
will be spared this affliction. However, if your dog does contract this
it is comforting to know that it is not fatal and recovery is merely a
matter of patience and tender loving care. Please note that a serious
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
be used to treat old dog vestibular syndrome include Cholodin Tabs and
Winstrol V. As always, check with your vet.
reprinted with kind permission from Patti Schaffner
Peoria Humane Society firstname.lastname@example.org
The vestibular system
controls balance and prevents an animal from falling over. It does this
by holding and constantly adjusting the position of the eyes, head and
body in relation to gravity. When there is disease affecting this
system, though it is seldom life threatening, the symptoms caused can
be particularly distressing for a pet owner. Animals may tilt their
head to one side, circle either clockwise or anticlockwise, fall over
repeatedly, roll to one side, be generally wobbly and display abnormal
pupil movement in their eyes. Here we look at the
physiology of the vestibular system in dogs and cats, what can go wrong
and how a good veterinarian will diagnose and treat it.
What exactly is the vestibular system?
The vestibular system is a sensory system consisting of a receptor
organ within the inner ear, the vestibular nerve itself, and a balance
control centre at the back of the brain. The receptor organ in the
inner ear detects the position and movement of the head in space, both
when the animal is resting or moving. Information on the position of
the head is converted into electrical signals, which are transmitted
via the vestibular nerve to the brain. The balance control centre in
the brain then processed this information, and sends motor signals to
the muscles controlling the positions of the eyes
and limbs according to the movement of the head.
What is vestibular syndrome?
Vestibular syndrome is a general term describing disease of the
vestibular system. The term alone does not provide any information on
which part of the vestibular system is affected, and what the cause is.
What are the signs to look out for?
Animals with vestibular disease may display any or all of the following
1. Head tilt
This is rotation of the head so that one ear is lower than the other.
It occurs due to loss of antigravity muscle tone on one side of the
Circling often occurs with vestibular disease, but can also occur with
forebrain tumors. Generally, tight circles mean vestibular disease
while wide circles mean a brain tumor.
3. Nystagmus (wandering pupils)
This means involuntary rhythmic movement of the eyeballs. The pupils
tend to drift to one side (the slow phase) and then jerk back to the
middle (the fast phase). Usually the slow phase is toward the diseased
4. Strabismus (squint)
This means abnormal position of the eyeballs, rather like the condition
commonly known as a squint.
5. Ataxia (wobbliness)
This means walking in an uncoordinated fashion, and is seen with a wide
range of diseases other than vestibular disease, such as those
affecting the brain, spinal cord or peripheral nerves. Animals can
adopt a broad based stance, exhibit swaying of the head, and leaning,
falling and rolling to
Peripheral vs Central Vestibular Disease
Vestibular disease is categorized as either peripheral or central,
according to where in the system the disease originates from.
Peripheral vestibular disease is where the disease is located in either
the receptor organs in the inner ear or the vestibular nerve. Central
vestibular disease is where the disease is located in the balance
control centre in the brain (to be precise, either in the brainstem
vestibular nuclei or in the cerebellum).
The first task for the veterinarian is to identify whether he/she is
dealing with peripheral or central vestibular disease. This is done by
carefully for all of the symptoms described above, and further
them by direction and nature. It is beyond the remit of this article to
go into the exact way of differentiating them clinically, and though it
can usually be achieved by a competent vet by examination alone,
further tests are necessary to do so.
Causes of peripheral vestibular syndrome
1. Middle or inner ear disease (infection or tumor)
2. Nasopharyngeal polyps
3. Head trauma
4. Drug toxicity (e.g. gentamycin)
5. Underactive thyroid gland
6. Congenital (present at birth)
7. Idiopathic (cause unidentifiable)
Causes of central vestibular syndrome
1. Brain hemorrhage or infarct
2. Infectious encephalitis (bacterial, viral or fungal)
4. Head trauma
5. Drug toxicity (e.g. metronidazole)
6. Brain cyst
7. Brain tumor (primary or metastatic)
8. Thiamine deficiency
9. Neurodegenerative disease
Making a diagnosis
First, the veterinarian must distinguish between peripheral and central
disease based on clinical signs. If there is doubt, diagnostics for
both should be done. If the veterinarian suspects central disease,
choose to rule out peripheral disease with various tests first because
tests for central disease are expensive (e.g. MRI or CT scan).
The following procedure is what is most commonly done when looking for
causes of peripheral vestibular disease. If drug toxicity has been
ruled out (no metronidazole, aminoglycoside antibiotics or topical
chlorhexidine recently) then the external ears are examined using an
otoscope (illuminated and magnified inspection device with a rigid
conical end which is inserted into the ear canal). Ear infections,
tumors and polyps may be detected this way. Middle ear disease is
suspected if the ear drum appears to be ruptured, bulging, cloudy or
red in color. Thyroid levels are usually measured by
a blood test at this stage to rule out hypothyroidism.
The next step of the investigation is taking xrays of the skull.
Several views are required but the most important one is that which
shows the tympanic bullae in the middle ears most clearly. This
requires general anesthesia to allow correct positioning.
If the tests at this stage have all come back normal, many cases will
be given a presumptive diagnosis of idiopathic vestibular syndrome.
This is usually because a) it is by far the most likely diagnosis, and
b) further specialized tests are costly. If however further tests are
to be carried out, MRI or CT scanning, electromyography and nerve
conduction studies are a possibility in some referral centers.
Author: Dr Matthew Homfray
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reprinted with kind permission from David Brooks
The above information is simply
informational. It's intent is not to replace the advice of a
veterinarian nor to assist you in making a diagnosis of your pet.
Please consult with your own veterinarian for confirmation of any
diagnosis. Your pets life may depend on it.