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Understanding Your Pet's
Epilepsy
Dennis O'Brien, DVM, PhD
Diplomate, ACVIM, Specialty of Neurology
University of Missouri, College of Veterinary Medicine
"All the most acute, most powerful, and most
deadly diseases, and those most difficult to be understood ... fall upon the brain."
|
--Hippocrates |
Epilepsy was recognized in ancient times and was undoubtedly one
of the "difficult" diseases Hippocrates referred to. Understanding what causes
seizures, how epilepsy is treated and how current research may help decrease the incidence
of the disease, will help you deal with the condition in your pet.
See your
veterinarian
Your veterinarian is
the person to ask what's best for your pet. |
· Your veterinarian will be your
best source for advice about your pet's health. They know your pet, what treatments have
been tried in the past, what was found on examination, and your pet's other medical
problems.
· Be an intelligent consumer.
Educate yourself about your pet's disease and don't be afraid to ask questions. If you
don't understand why a test is being run or a treatment recommended, your veterinarian
will be able to explain why this will help your pet.
· Remember anyone can post
anything on the Internet so there is no guarantee the information is valid unless it comes
from a reputable source. Share what you learn with your veterinarian. They can help you
distinguish information that may be helpful from ideas that may be useless or even
dangerous for your pets individual needs.
· The information in this
site is provided to help you understand the things your veterinarian will be discussing
with you and may help stimulate discussion of the options available.
· We cannot directly advise
you on how to treat your pet. If your pet is having serious problems, you may wish to ask
your veterinarian to refer you to a nearby Veterinary Neurologist (a specialist in
diseases of the nervous system like epilepsy). To find a Board Certified Neurologist near
you, go to the American College of Veterinary Internal Medicine homepage and search the "Find an ACVIM specialist near you"
database. Information about the neurology service at the University of Missouri, College
of Veterinary Medicine can be found at www.vmth.missouri.edu
Key points
If you have a pet with epilepsy, these are some of the
key points for you to remember. They are discussed in more detail elsewhere:
· Don't
change or discontinue medication without consulting your veterinarian.
· See your
veterinarian at least once a year for follow-up visits.
· If your
pet has a seizure longer than 5-10 minutes or 3 seizures in a day, seek veterinary care
immediately.
· Be
skeptical of exorbitant claims of treatments.
· Remember,
live with epilepsy not for epilepsy. With appropriate treatment, most dogs
have far more good days than bad ones. Enjoy all those good days! Enjoy your life and your
pet. They have a serious disease, but don't let that keep you from enjoying the time you
have with them.
What is epilepsy?
Epilepsy refers to
repeated seizures over time. Idiopathic means we can't find an underlying cause of the
seizures |
Epilepsy simply refers to repeated seizures.
Seizures may occur as a one time event in an animal from a variety of causes, but only if the seizures
repeat again and again over a period of time do we call it epilepsy. Seizures are a sign
of brain disease the same way a cough is a sign of lung disease. Saying an animal has
epilepsy is like saying it has a chronic cough; it is a sign of a problem which isn't
going away. Anything which damages the brain in the right area can cause epilepsy. If we
can identify the cause of the seizures, say a brain tumor or a stroke, then we say the pet
has symptomatic (or secondary) epilepsy. That is, the seizures are a symptom of a disease
process we've been able to identify. If we've looked and can't find the cause, then we
call it idiopathic (or primary) epilepsy. The term idiopathic simply means that we
don't know the cause. It may be that the cause has escaped our attention; for example, a
stroke that is too small to detect with routine brain scans or damage that occurred during
whelping.
Many of the idiopathic epileptics have inherited epilepsy: epilepsy
caused by a mutation in a specific gene which they inherited from their parents. Dogs with
idiopathic epilepsy frequently begin seizing at between one and three years of age, and
certain breeds are predisposed to develop epilepsy. A few breeds have proven hereditary
epilepsy, while in most it is just a strong suspicion. One of the goals of the Canine Epilepsy Project is to
identify genes responsible for epilepsy in dogs. This will allow us to positively diagnose
the hereditary form and take steps to decrease the incidence of epilepsy in dogs.
How common is epilepsy?
Epilepsy is one of the most common neurologic diseases in dogs, but no one knows for
sure just how common it is. Some studies estimate up to 4% of all dogs are affected. In
some breeds, the incidence may be higher and some families may have up to 14% epileptics.
Epilepsy occurs less frequently in cats and other pets, presumably because they do not
have a hereditary form of the disease.
What determines when my pet will
have seizures?
No one knows what it is that determines when an epileptic will have seizures. The only
thing we can predict about epilepsy is that it's unpredictable. Some pets appear to have
seizures very regularly, while in others, the seizures appear to be precipitated by
specific events such as stress, or changes in the weather. However, when we try to use
what's happened in the past to predict when the next seizure may occur, we usually aren't
very successful. For many epileptics, there is no pattern to their seizures.
How do we diagnose idiopathic
epilepsy?
Minimum work-up for an epileptic |
History |
Your description of the
character and timing of the episodes, relation to exercise, feeding, etc. |
Helps your veterinarian
determine if this is indeed a seizure and what type. May provide clues to the cause |
Physical
examination |
Evaluation of the heart,
lungs, abdomen, gum color, etc. |
Provide clues to diseases
which could cause seizures or complicate treatment |
Neurologic
examination |
Evaluation of behavior,
coordination, reflexes and nerve functions |
Provide clues to disease of
the nervous system which may be causing the seizures |
Complete blood count (CBC), routine serum chemistry profile, and urine
analysis (UA) |
Blood and urine samples are
taken and analyzed |
Rules out metabolic causes
of seizures and provides baseline data to monitor effects of medication |
Bile acids assay or ammonia tolerance test |
Usually, the pet is fasted
and two blood samples are taken |
Rules out liver problems and
provides baseline data to monitor effects of medication |
Thyroid function tests |
Blood samples analyzed for
T4 and TSH levels |
Optional, but would rule out
thyroid disease as a cause |
Idiopathic epilepsy is a diagnosis by elimination. That is, we
look for other causes of seizures and if we can't find any, we make the diagnosis of
idiopathic epilepsy. How aggressively we search for an underlying cause is a matter of
clinical judgement. We always recommend a minimum work-up for any dog having seizures.
This will provide us with clues to a possible underlying disease and provide the baseline
from which to watch for potential side effects of antiepileptic drugs.
Since your veterinarian may not witness one of your pet's seizures, they are very
dependant upon your description of the episode. This will help them decide whether these
events are indeed seizures. Other problems such as fainting or dizzy spells can also come
and go like seizures and may look similar to the untrained eye. Thus, your veterinarian
will need a clear description of what you observe during the episode to help make that
distinction. They will also be determining what type of seizure your pet is
experiencing. Write down a description of what you saw as soon as possible after the
episode. If you can, make a videotape of the episode to show your veterinarian or the
neurologist.
In order to rule out some diseases, we would need further tests. If the animal is
outside the 1-3 year old range when idiopathic epilepsy typically starts, or has any
abnormalities on examination that hint of a cause, we strongly recommend such testing.
Your veterinarian may refer you to a neurologist for some of these tests. Even if an
animal is within the "idiopathic epilepsy" age range, we can't be sure it's
idiopathic unless we perform the full compliment of tests. One study (Podell 1995) showed
that over 1/3 of the dogs between 1 and 5 years of age had an identifiable cause for the
seizures. Thus we can make a case for aggressive testing in any epileptic dog, but need to
weigh the additional cost involved into the equation.
Other tests that may be recommended
(may require referral to a neurologist) |
MRI or CT brain scan |
Evaluate the structure of
the brain; requires anesthesia |
Rules out diseases such as
brain tumors which would need to be treated directly |
Spinal tap |
Spinal fluid is collected
and analyzed; requires anesthesia |
Looks for infectious
diseases and provides clues to other brain diseases |
Antibody titers |
Blood and/or spinal fluid is
analyzed for antibodies |
Identifies specific cause of
an infection |
Toxin tests |
Blood or other sample is
tested for the presence of a toxin |
Tells if a specific toxin is
present, but usually need a clue to what toxin to look for from the history or other test |
Other laboratory tests |
Advanced tests on blood,
urine, or spinal fluid |
Follows clues suggested by
routine tests |
Electroencephalogram (EEG) |
Recording of brain wave to
look for the electrical storm |
Allows definitive diagnosis,
but can be non-diagnostic |
The electroencephalogram (EEG) is a useful tool in diagnosing
epilepsy, but has serious drawbacks in animals. When we see abnormalities in the EEG, that
tells us this is indeed a seizure and may help us pinpoint the source. The trouble is,
those EEG abnormalities, like the seizures, can come and go. If they don't happen while we
are recording the EEG, we will not see them. Recording an EEG in an awake animal is
difficult, so we often have to sedate or anesthetize them to get an adequate recording.
The drugs used for the sedation/anesthesia also affect the EEG. Thus, we often make the
diagnoses of epilepsy based on the clinical signs and don't require EEG confirmation of
the disease.
Thyroid function and epilepsy
There is a great deal of controversy (largely unnecessary) about the role of the
thyroid in canine epilepsy. The thyroid hormones regulate metabolism. Too much thyroid
activity, and the metabolism runs too fast. The result is weight loss, nervousness, high
blood pressure, and so on. Too little thyroid activity, and metabolism runs too slow. This
results in weight gain, lethargy, high cholesterol levels, and so on. Normally, dogs don't
develop atherosclerosis: the hardening of the arteries that predisposes people to heart
attacks and strokes. The high cholesterol that accompanies hypothyroidism (too little
thyroid hormone) can, however, lead to atherosclerosis and strokes in dogs. Likewise the
high blood pressure that accompanies hyperthyroidism (too much thyroid hormone) can also
predispose the dog to stroke. So the dog needs "Goldilocks levels" of thyroid
hormone: not too much, not too little, but just right. If the levels are outside that
range, then we could have problems which could cause epilepsy.
Thyroid function tests are affected by many things, including stress and medications.
Several recent studies have demonstrated that phenobarbital therapy causes falsely low
values on some thyroid tests. Recent seizures will also cause false lowering of the
values, presumably due to the stress they cause. So test results need to be interpreted
with these caveats in mind. If an animal tests truly low on thyroid function, then a trial
of thyroid supplementation is indicated. If an animal has normal thyroid tests or fits
with what we expect from the effects of the medication or seizures, then there is no
reason to supplement thyroid hormones.
What about liver shunts?
|
In this radiograph, blood (shown
in white)
flows through a shunt (arrow) bypassing
the liver (star). |
One of the jobs of the liver is to ensure that only the good
stuff from the food we eat gets into the body. Dogs are notorious for eating disgusting
things, such as the moldy cheese out of the garbage, and their liver is responsible for
keeping toxins from affecting the body. In addition, the action of bacteria in the
intestines on food can produce toxic byproducts which the liver deals with. All the blood
coming from the intestines goes through the liver first, where it is cleansed of toxins
before going around the rest of the body. When an embryo is safe in the mother's womb, the
mother's liver takes care of that job, and the embryo doesn't need to worry about it. As a
result, the blood from the intestines bypasses the liver in the embryo through a separate
vessel called a shunt. When the pup is born, however, the liver needs to switch gears and
start doing it's job of cleaning the blood from the intestines. So the shunt closes down
and blood is run through the liver to be cleansed before it gets to the brain.
If the shunt fails to shut down like it should, then blood will continue to bypass the
liver. A shunt that is present from birth is called a congenital shunt. The liver then
doesn't get a chance to remove the bad stuff until it's already circulating around the
body. Many of the toxins that the liver would normally clean up can affect the brain, and
seizures can be one of the effects.
Shunts can also be acquired later in life. If the liver is diseased, blood may have a
hard time flowing through the sick liver, leading to a back-pressure in the vessels coming
from the intestines. If that back-pressure gets high enough, the blood may find an
alternative, less resistant, pathway. The result is the same as the congenital shunt;
blood bypasses the liver and toxins affect the brain.
Both because liver problems can cause seizures and because many of the medications used
to treat epilepsy can injure the liver, we recommend liver function tests as part of the
initial work-up and as part of the regular check-ups. The liver enzyme tests which are
part of a routine chemistry profile may not be adequate to detect liver shunts and liver
function tests, such as bile acids or ammonia, are necessary.
Other tests may be necessary
Depending upon your pet's age, type of seizure, and findings on the minimum work-up,
your veterinarian may also recommend further tests. Advanced imaging, such as MRI or CT
scans, is necessary to be able to actually see the brain. Regular radiographs (X-rays) can
tell us about the bones of the skull, but not the brain itself. Such imaging is becoming
more readily available for animals at referral centers. By imaging the brain, we can
diagnose diseases such as brain tumors or hydrocephalus (water on the brain) which can
cause seizures.
Infection of the brain (encephalitis) can cause seizures. Canine distemper is the most
common cause of encephalitis in dogs and one of the reasons to keep your pets current on
their vaccinations. A spinal tap and serum antibody titers will enable your veterinarian
to tell if distemper or one of the other causes of encephalitis is the reason for your
pet's seizures. Additional blood tests including toxin screens may also be indicated.
What is a
seizure?
The balance of inputs
to a nerve cell determines how excitable it will be. |
Seizures are caused by an electrical storm in the brain. Normal
brain cells (neurons) use electrical and chemical signals to communicate with each other.
This communication can either be excitatory, tending to activate the next neuron,
or inhibitory, tending to shut the next neuron off. A delicate balance of these
excitatory and inhibitory influences on any given neuron determines whether it is going to
become activated and pass information on to other neurons. If the balance within the brain
shifts too far toward excitation, too many cells may become too excited and a seizure can
result. Keep in mind, we are talking about excitation or inhibition of individual neurons
in the brain, not whether your pet's excited to see you when you get home. In fact,
seizures in dogs occur most commonly when the pet is relaxed or asleep, although they can
occasionally be associated with exercise or emotional arousal.
|
An
imbalance can cause an electrical
storm in the brain which we see
on the EEG. |
We can see this excess excitation if we record the electrical
activity of the brain through an electroencephalogram (EEG). On the EEG, the seizure will
appear as a series of sharp spikes as waves of excitation overtake the brain. This
electrical storm then causes changes in the behavior and movement of the animal which we
recognize as a seizure. There are several different types of seizures depending upon the
nature and location of the electrical storm.
Types of seizures
Seizures are broadly divided into two types; generalized and partial (or focal) seizures. In a
generalized seizure, the electrical storm appears to arise everywhere at once. In a
partial seizure, the abnormal electrical activity arises in a small area of the brain.
Since your veterinarian may not see one of the seizures, they will rely on your
description of what your pet does during the seizure to help them classify it. The
descriptions provided here will help you understand the types of seizures, but don't jump
to conclusions. Describe for your veterinarian or the neurologist exactly what you
observe.
Generalized, tonic-clonic (grand
mal) seizures
Generalized seizures
begin over the entire brain simultaneously. |
Generalized seizures are further divided into two sub-types:
major motor seizures (grand mal) and absence seizures (petit mal). The major motor seizure
is the classic seizure. It is also sometimes called a tonic-clonic seizure. A classic
seizure can have three phases, the aura or prodrome, the seizure itself (sometimes called
the ictus) , and post-ictal
(post-seizure) behavior. Not all seizures have the three phases, but commonly they will.
The most common time for a dog to have a seizure is when they are relaxed and quiet.
They may even occur from a sound sleep. Seizures can occur anytime, but if they occur only
when an animal is excited or exercising, it may indicate a heart problem or low blood
sugar.
Just as some dogs can sense when their epileptic owner is going to have a seizure, some
owners can sense when their epileptic dog is going to have a seizure. The aura or
prodrome is a recognizable change in the pet's behavior that alerts the owner to an
impending seizure. Most commonly, the pet that has an aura will act upset and anxious. He
may seek attention from his owner or withdraw and hide. This aura may represent a focal
beginning of the seizure and thus indicate a partial seizure, but we commonly see it in
generalized seizures as well.
When the seizure
begins, the dog stiffens and falls; They then begin jerking movements
They are not in pain during the seizure and cannot control their bladder or bowels. |
The classic seizure itself is called a tonic-clonic seizure.
It begins with a stiffening of the muscles (the tonic part). Usually the pet will fall to
their side with the legs stretched out and the head back. Once the seizure has begun, the
pet is no longer conscious even though his eyes may remain open. Sometimes they will
vocalize or the face may twitch. The vocalizations are involuntary and do not indicate
pain. Often he will drool excessively or he may urinate, defecate, or empty his anal
glands causing a foul smell. He has no control over these "accidents" and is
completely unconscious during the seizure. This tonic phase is usually very brief (less
than 30 seconds) and gives way to rhythmic movements (the clonic part). Typically this
consists of chomping of the jaws and jerking or running movements of the limbs. Often he
will not breath well during the seizure and the tongue may turn blue. Even though the
seizure may seem to go on forever, the average seizure lasts less than 2 minutes. If the
seizure goes on much longer, we become concerned that the pet may go into a continuous
seizure (an emergency situation).
Post-ictal behavior
Following the seizure, the pet may lay motionless for a period of time. Eventually they
get back on their feet. He may bounce back and be perfectly normal afterwards, but more
typically there is a period of post-ictal behavior. Often the pet appears blind and
disoriented during this post-ictal phase. He may pace or run about the house, bumping into
things as he goes. Sometimes they are excessively hungry and will devour any food
available. Rarely, a dog may behave aggressively during this period, especially if they
are restrained. While such aggressive behavior is rare, it is important to recognize the
possibility, especially if the dog is large and there are children in the household.
Usually this post-ictal behavior begins to resolve within a few hours after the seizure
and the dog gets back to normal.
Variations on the theme
Not all generalized seizures follow this pattern. Some won't show any aura but strike
out of the blue. Some pets bounce back immediately after the seizure as if nothing had
happened, while others may be disoriented for days. Some may show only tonic rigidity
during the seizure itself, while others may show only clonic jerking and paddling. More
rarely still, the pet may simply drop limply to the ground and lay motionless. A
"drop attack" like this is more typical of a fainting spell, but can occur with
seizures.
Cluster seizures and status
epilepticus
Most seizures are brief and isolated, but sometimes they can be more serious. The
large-breed dogs tend to have clusters of seizures. In these cases, the dog will have one
seizure and recover from it. Then a few hours later, they have another. They never
completely recover before another seizure strikes. Then they have another seizure, then
another seizure, then another, another, another.... Sometimes this culminates in a
continuous seizure that doesn't stop, a condition called status epilepticus.
Occasionally status epilepticus can arise out of the blue; the animal begins seizing and
never stops. Either way, this is a true emergency requiring immediate veterinary care.
(See what do you do if your pet seizures).
Effects of seizures
Most seizures are brief, and with proper treatment, the pet can lead a normal life.
None-the-less, seizures are serious business and even short seizures can cause brain
damage. That damage tends to be cumulative over time. If the seizures are short, the main
effect is an increased chance of another seizure in the future. Thus, there is a tendency
for epilepsy to get worse over time, especially if left untreated.
If a seizure goes on for more than 30 minutes, the pet is liable to suffer serious
permanent brain damage. This can be manifest as a change in personality, or loss of memory
for things such house breaking. Occasionally the pet may be left in a coma from the
seizures. The seizure also creates a tremendous stress on the heart and other organs. The
body temperature may get very high from all the muscle activity and the animal may not
breath adequately. Sometimes the stress is too much and the pet may have a heart attack
and die. Fortunately this is rare.
Absence (petit mal) seizures
Petit mal or absence
seizures cloud consciousness without convulsions. They don't appear to occur in pets. |
The other type of generalized seizures in people is the absence
or petit mal seizure. Petit mal seizures differ from other seizures in several important
aspects. First there is little movement during a petit mal seizure. As the name
"absence" implies, the person simply loses contact with the world during the
seizure. They stare blankly and may blink but do little else. Absence seizures are also
different in that they probably represent a storm of inhibition rather than a storm of
excitation within the brain. This creates a unique EEG pattern. This means that very
different drugs are used to treat petit mal seizures. We're not sure if petit mal seizures
really occur in pets. Most of the seizures that are called petit mal seizures in pets are
actually partial seizures.
Partial seizures
|
A partial
seizure begins in a localized
brain area which we can detect with the EEG. |
In partial or focal seizures, the electrical storm begins in an
isolated area of the brain. If we are recording an EEG at the beginning of such a seizure,
we can see the storm starting in one part of the brain. A partial seizure may stay
localized, or it may spread and affect the whole brain causing a classic, generalized, tonic-clonic seizure.
In some cases, the aura preceding a generalized seizure may actually be a partial seizure.
The fact that the seizure starts in a local area suggests that localized damage has
occurred. As a result, when we see partial seizures, we are more worried about diseases
which will cause local damage, such as a brain tumor or infection. Partial seizures are
further divided into two subtypes (simple or complex) depending on where the storm
originated and how it affects the pet.
Simple partial seizures
|
This MRI scan of the
brain shows a tumor
in a dog having
simple partial seizures. |
Simple partial seizures (also sometimes called minor motor or
focal motor seizures) originate in the area of the brain that controls movement. A
localized storm in this area results in movement of the area of the body controlled by
that part of the brain. Most commonly, the face is affected resulting in twitching or
blinking. This is usually limited to one side of the face. If the seizure spreads a bit,
other parts of the body on that side will be affected. For example, the front limb may
then begin to twitch and buckle. During a simple partial seizure, the pet is usually alert
and aware. They may attempt to seek out their owner, confused about what is happening. The
seizure may stop there or it may generalize. If it generalizes, the pet loses
consciousness and has a classic grand-mal seizure.
Example of a partial seizure
Here is a video clip which shows a partial seizure. Watching this clip may upset some
people. We present it because we think it is important for owners to be able to accurately
describe to their veterinarian what type of seizure their pet is having. The dog pictured
suffered from a brain tumor and was receiving intravenous medications to stop the seizures
while the tape was being made; hence the white bandage on the arm. The seizure consists of
twitching of the face and jerking of the head. Note that the face twitching occurs
primarily on the left side of the face. Click here to begin video. This clip is
4,700 kb and thus may take quite a while to load. You may wish to finish reading and come
back to the video when your done.
Complex partial seizures
Most aggression is a
behavior problem and a behavior specialist should be consulted. |
Complex partial seizures originate in the areas of the brain
that control emotions and behavior (the temporal lobes) and are sometimes called
psychomotor seizures. When a seizure begins in one of these areas, the animal's
consciousness is altered and they behave bizarrely. They may run uncontrollably, engage in
senseless, repetitive behavior, or rarely fly into a rage. Other times, we see bodily
functions affected and the pet may have diarrhea or vomit. Following a typical generalized seizure, unusual
behavior (post-ictal
behavior) is common and may go on for hours. Complex partial seizures, like other types of
seizures, are typically very brief.
Most often, an animal behaving aggressively or acting strangely has a behavioral
problem or some other reason for the change in behavior. If, however, these changes occur
as discrete episodes, and the pet also has a generalized seizure, we can be sure that this
is a complex partial seizure and treat it accordingly. People with complex partial
seizures may experience hallucinations. Some dogs have episodes of fly-snapping where they appear to
be biting at imaginary flies around their head. Some of these may be complex partial
seizures although we cannot tell for sure.
What causes
seizures?
Many things can tip the balance between excitation and
inhibition in the brain toward too much excitation. Keep in mind, we're talking about the
excitatory influences on nerve cells in the brain, not the dog's emotional state. Once a
certain threshold of excitation is passed, any animal may seize. Things that can push an
animal past that threshold include toxins, metabolic diseases, and direct damage to the
brain.
Some plants have evolved toxins which cause seizures as a defense against
insects or other plant eating animals. If your pet eats such plants, they could be
similarly affected. We utilize some of these plant toxins and related chemicals as
insecticides to protect our pets from fleas and our tomatoes from horn worms, and these
insecticides can cause seizures if used inappropriately. Other toxins, such as lead and
some industrial chemicals, can also cause seizures. Thus your veterinarian will need to
know about potential exposures to these compounds if your pet has a seizure.
The metabolic state of the pet will also influence the brain and can secondarily
cause seizures. If the brain doesn't get an adequate supply of oxygen and nutrients to
fill its needs, the excitability of the cells may increase and seizures result. Thus low
blood sugar or heart disease may cause seizures. Electrolytes (different salts normally
present in the body) play important roles in brain function. Alterations of these
electrolytes (particularly sodium and calcium) can cause seizures. Low calcium levels can
be a problem in a nursing mother. Toxic byproducts are constantly being produced in our
body from normal activities of the organs. The liver and kidneys have the job of getting
rid of these toxic byproducts. If either of these organs isn't able to do its job, these
byproducts can accumulate and seizures may be one of the results. If your pet is having
seizures, your veterinarian will recommend blood tests both to determine if one of these
metabolic disease is the cause and to provide a base line to watch for potential side
effects of the antiepileptic drugs which may be used.
Physical damage to certain areas of the brain can produce an epileptic focus.
This is a small area of the brain that initiates partial seizures which in turn can lead
to generalized seizures. We don't know how local damage causes the electrical storm in
that area, but we do know that many types of damage can have this effect. Thus head
trauma, brain tumors, infections in the brain (encephalitis), strokes, just about anything
that damages the brain can lead to seizures. If your veterinarian suspects such brain
damage as the cause, they may refer you to a veterinary neurologist for brain scans,
spinal taps or other tests to be sure there isn't a brain tumor or other explanation for
the seizures. We become especially worried about such acquired damage if the dog falls
outside the age range where we typically see hereditary epilepsy, that is if they are less
than a year or more than 3-5 years old. Sometimes removing the cause of the damage cures
the epilepsy. Other times, the damage has been done, and even if we can remove the tumor
or control the infection, the pet is left with epilepsy. Even if we don't cure the
epilepsy, the seizures will be easier to control without the continuing damage from an
untreated tumor or infection. In addition, such a disease left untreated may well cause
other, potentially even more serious problems.
Hereditary
epilepsy
Any animal may have a seizure if the "seizure
threshold" is passed by too much excitation in the brain. In addition to the external
metabolic influences, there are internal factors in a neuron that regulate how excitable
that cell is. The makeup of all the internal machinery of the neuron and its interactions
with its neighbors is determined by the genetics of the animal. A mutation in certain
genes can cause these cells to be more excitable and thus more likely to slip over the
threshold into seizures. We presume that this is the basis of hereditary epilepsy, but
until we find the genes responsible, we won't know for sure. Even dogs with hereditary
epilepsy only seizure intermittently. Other influences that we don't understand regulate
when that lower seizure threshold will be crossed and an actual seizure occur.
When we see multiple
epileptics in a family, we begin to worry that it may be hereditary.
In this pedigree, epileptics are shaded. |
Epilepsy has been proven to be hereditary in several breeds and
it is suspected in numerous other breeds. Right now, we don't know exactly how epilepsy is
inherited in dogs. It may well be that there are different modes of inheritance and
different genes involved in various breeds and families. Preliminary results from the Canine Epilepsy Project suggest
that there are two or more genes involved in some of these families. There are several
genes associated with epilepsy in humans and mice, and these genes are being investigated
as possible candidates for the culprit in canine epilepsy. You can help with this project
by alerting us to families with epilepsy which fit the criteria for useful research families.
How is epilepsy
treated?
Ideally, we would like to be able to remove the cause of
the epilepsy so that the animal will never seizure again. If the epilepsy is symptomatic,
sometimes treating the underlying disease (for example, removing the brain tumor) will
cure the epilepsy. More often than not, we either can't find the cause (idiopathic
epilepsy) or even if we can find and eliminate the cause, some damage has been done and
the epilepsy continues. Then we need to use medications to control the seizures.
Goals of therapy
Antiepileptic drugs do not cure epilepsy; they simply control the seizures. Since we
are controlling the seizures rather than eliminating the disease, plan on life-long
therapy. The goal of therapy is to decrease the number and severity of the seizures. In
particular, we strive to eliminate the clusters of seizures which can create
life-threatening situations. Even a well controlled epileptic will have seizures now and
then. If we can decrease the frequency and severity of the seizures to a tolerable level
without producing side effects of the medication, we consider that a success. Epilepsy is
successfully controlled in over 2/3 of the epileptics treated. While not bad odds, that
leaves entirely too many patients that still have difficulty with seizure control.
Patience is necessary when treating epilepsy. Antiepileptic drugs are not "one
size fits all" medications. They need to be individualized to your pet's specific
needs. Often this requires some trial and error to find the medication and dose that works
best for your pet. This "perfect balance" may also change with time. When we
start medication or alter the dose, it takes time for the drugs to have their maximum
effects. There will be some seizures even with the medication, and we need to see how
frequently the seizures are occurring to judge just how effective the medication is.
Patience is hard to come by when your pet is having terrible seizures, but if your
veterinarian advises you that you must wait things out, it may be necessary to do so.
The objective of treating epilepsy is to tip the balance of excitation and inhibition
in the brain toward less excitation. The most commonly used drugs in dogs are
phenobarbital, potassium bromide, and diazepam. These drugs may be used separately, but
sometimes combinations are needed. They all act to increase inhibition in the brain, thus
making seizures less likely. This increased inhibition comes at a price, however, and all
the antiepileptic drugs may have side effects such as sedation and appetite stimulation.
When do we begin treating?
Any decision to begin a therapy involves weighing the risk of not treating the disease
against the risk of side effects of the medication. Many factors weigh into this decision,
but in general, if a pet is having more than one seizure every couple months, risk of
brain damage and worsening of the epilepsy tips the scales toward treating. If the pet has
had clusters of seizures or status epilepticus, then we are very concerned about the risk
of a life threatening seizure as well. Other factors we take into consideration include
the general health of the pet, the home environment, and economic considerations.
Will I ever be able to stop
treating?
Most epileptics require life-long therapy to control their seizures. Occasionally we
have animals that can be weaned off medication and don't seize again. These are usually
the cases where a cause of the seizures was identified and treated, but sometimes we get
lucky with other cases as well. We need to be very patient, though, before deciding that
an animal can come off medication. If the medication is doing it's job, the pet may have
very few seizures, thus we want to see them go for many months without a seizure before we
start to ask if they need the medication or not. If we do decide to try withdrawing
treatment, we must do so very slowly and be ready to go back if problems develop. Your pet
becomes dependant upon the medication and stopping it suddenly could precipitate serious
seizures.
NEVER DISCONTINUE ANTIEPILEPTIC
MEDICATION WITHOUT CONSULTING YOUR VETERINARIAN!!!
What are the
commonly used treatments?
All the commonly used medications for epilepsy act in the
brain to tip the balance away from excess excitation. The most commonly used drugs include
phenobarbital, potassium bromide, and diazepam.
Phenobarbital and primidone
Phenobarbital is probably the most commonly used antiepileptic drug in dogs. In
addition to being used on a daily basis to prevent seizures, phenobarbital (or its first
cousin pentobarbital) is often used to stop seizures in progress. Primidone is another
medication which is actually converted to phenobarbital by the body and thus acts
virtually the same way. Phenobarbital is a very effective antiepileptic drug. It is not
expensive and comes in liquid form as well as different size tablets. This makes it easy
to come up with the correct dose for everything from a Chihuahua to a Great Dane. It works
well in dogs because it stays in the body long enough that it usually only has to be given
twice a day.
Most pets have very few side effects on phenobarbital. When we first start them on the
medication, we expect them to be a bit sedated and a little unsteady on their feet, but
usually they develop a tolerance to the sedative effects within a few days. Sometimes the
dose needs to be increased to control the seizures, and then the dog may have side effects
again. The sedative effects are the main reason phenobarbital isn't used more often to
treat people with epilepsy. If the child falls asleep at school, or the parent falls
asleep driving home from work, that's a problem; if the dog wants to nap in the afternoon,
that's usually not so bad.
The other common side effect is a stimulation of thirst and appetite. Decreased
activity plus increased food intake, can equal obesity. It is important to watch their
food intake so that they don't become overweight.
Phenobarbital is eliminated by the liver and this can take its toll on the liver over
time. Some dogs may develop liver damage with long term use of the drug, but many dogs
never have any liver problems. Monitoring liver function tests on a regular basis will
help avoid potential problems.
Potassium bromide
In 1857, Queen
Victoria's physician found that bromide helped epilepsy. |
Bromide was actually one of the first antiepileptic drugs
discovered dating back to Victorian times. It was largely abandoned by physicians when
phenobarbital was invented because it caused psychological problems in people. It was
rediscovered by veterinarians about 100 years after it's first use in people and it has
proven to be a valuable antiepileptic drug in dogs. Dogs do not appear to suffer the
psychological side effects of bromide that people do.
Because it has been around for so long and is seldom used in people anymore, bromide
has never received the FDA (Food and Drug Administration) stamp of approval as a drug.
Since no one can patent its use, it is unlikely that any pharmaceutical company will go
through the trouble and expense of getting bromide approved. Veterinarians obtain special
permission from the FDA to use it. Although it has never gone through the rigorous testing
required by FDA for approval, bromide has been used in dogs for a long time now, and has
proven to be a reliable drug.
Bromide is combined with either potassium or sodium (KBr or NaBr respectively) to form
a crystal that looks like table salt. This powder can be packaged into capsules, but is
much easier to simply mix it with water to form a solution. This solution is very stable
and does not need to be refrigerated. The liquid also has the advantage of making
adjustments in the dose easy. Since bromide can have bad effects on people, handle it
cautiously. Keep the solution away from children and avoid getting the solution on your
skin.
Bromide has a very long half life; that is, it takes a long time for the body to
eliminate the drug. This means that we usually only need to give the drug once a day which
makes it very convenient. It also means that it takes quite a while from when we begin the
drug, until we see the maximum benefit of it. We can get quicker results by giving a much
higher dose (a loading dose) initially, but we may see more side effects if we do. So
generally we take our time and only do the loading dose when necessary. Because the
bromide hangs around so long in the body, we also need to watch the dose and monitor the
blood levels to avoid overdoing it.
The amount of salt in the diet can influence how quickly bromide is eliminated from the
body. Thus a dog receiving bromide therapy should remain on a consistent, quality dog food
diet and salty treats (which includes most table scraps) should be avoided.
Bromide can sometimes cause an upset stomach, and thus it is best given at meal times.
The liquid can be mixed with food as long as the dog will eat it all. If the dog is a
picky eater, mix the bromide with a little food and wait until that's gone to give the
remainder of meal. Alternatively, simply give the liquid directly into the dog's mouth.
Bromide can cause drowsiness and stumbling like phenobarbital. Usually we only see this
when we first begin the medication or at higher doses. The dogs usually develops tolerance
to the sedation with time, and if not, decreasing the dose can correct the problem.
Sometimes the higher dose is needed to control the seizures and then we're faced with
deciding between the lesser of two evils. Increased appetite is also common. Rarely skin
problems have developed.
Diazepam and related drugs
Diazepam is the generic name for Valium. Most people think of Valium as a tranquilizer,
but diazepam is also a very effective drug for treating seizures. The trouble with
diazepam is that if it is given daily, it tends to lose its effectiveness over time. As a
result, we usually reserve it for stopping a seizure in progress rather than using it as a
daily, preventative medication. We occasionally use diazepam or one of the related drugs
(clonazepam or clorazepate) on a daily basis, but only when other medications are not
working alone.
The best way to give diazepam to stop an active seizure is by an intravenous injection.
Diazepam can also be very effective when given per rectum. This refers to giving the
medication into the rectum (like a suppository) where it is rapidly absorbed through the
membranes. Suppository forms of diazepam are available, but they are fairly expensive, so
we usually just use the liquid form that is used for injections. It's not the most
pleasant way to administer medication, but this approach can often help dogs that have
clusters of seizures. By giving the diazepam at home when the dog begins their cluster,
further seizures can often be prevented, thus saving an emergency trip to the
veterinarian.
Newer antiepileptic drugs
Many pet owners know a human epileptic who is taking Tegretol, Depakote, Dilantin or
other medications for their epilepsy with good success and wonder why those drugs are not
used for their dog. Dogs and people are different in ways besides how furry they are and
how many legs they walk on. The way a dog eliminates drugs from the body may be very
different from a person. For many of the newer antiepileptic drugs that work well in
humans, dogs eliminate them from their bodies much quicker than people do. Thus in order
to receive the same benefits, a dog would have to take the drug more frequently than a
person would have to take it. Combined with the high price tag for these new drugs, this
often makes them impractical. One of the newer antiepileptic drugs, lamotrigine, can be
toxic to dogs even though it is not toxic to people. Still, we are constantly looking for
better treatments for epilepsy in dogs, and several are currently being evaluated. Some of
the newer drugs which may prove useful in dogs are felbamate, gabapentine and topiramate,
but the jury is still out, and they should only be considered when conventional treatments
fail.
Other treatments
Other treatments are also being looked at for treating epilepsy. These include surgery,
vagal nerve stimulation and special diets.
Surgery will be of definite value if we are dealing with epilepsy secondary to
something like a brain tumor where removing the cause might cure the epilepsy. In human
medicine, they can sometimes identify a focal source of the epilepsy (the epileptic focus)
even when it is not a clear, structural lesion like a tumor. Surgery to remove the
epileptic focus is sometimes attempted if these people have intractable epilepsy. While
such surgeries have sometimes been successful in humans, they are still experimental in
canine epilepsy.
The vagus is a large nerve in the neck that brings sensory information from many of the
body's organs to the brain. Stimulating the nerve electrically, much the way a pacemaker
is used to stimulate the heart in some heart disease, may help to control epilepsy. This
approach is currently being studied to see if it will work in dogs.
In people, a diet very high in certain fats will produce a condition called ketosis and
is called a ketogenic diet. The ketogenic diet can help control some seizures in people,
but has not yet been shown to help epileptic dogs. Such a diet has to be carefully planned
to make sure that other essential nutrients aren't short changed and simply adding excess
fat to a dog's diet will make them obese without benefiting their epilepsy.
Side effects of antiepileptic drugs
Most epileptics experience very few side effects of their medication. When side effects
do occur, they are usually mild and are far outweighed by the risk of further seizures if
we don't treat the epilepsy. Because they increase inhibition in the brain, the drugs tend
to be sedatives. This is particularly apparent when the medication is started or when the
dose is increased. The dog may be lethargic and want to sleep all the time. The drugs can
also affect coordination causing the dog to stumble and weave as if drunk. Most dogs
develop a tolerance to the sedative effects of the drugs within a week of beginning them
or increasing the dose. Thus if these signs are mild, we will usually try to wait them out
and usually within a few days, they improve. Sometimes, decreasing the dose of the
medication is necessary, but we always weigh the risk of more seizures into the decision.
NEVER CHANGE THE DOSE OF
ANTIEPILEPTIC MEDICATION OR DISCONTINUE IT WITHOUT CONSULTING YOUR VETERINARIAN!!
The animal on antiepileptic drugs becomes dependant on
the medication and sudden decreases in the dose can precipitate serious seizures. When a
medication is discontinued, this must be done gradually if the dog has been on it for any
length of time.
Occasionally, dogs have a paradoxical reaction to the medication. Rather than becoming
sedated, the dog becomes restless, agitated and rarely irritable. They may pace around the
house unable to relax or sleep. Why some animals respond this way is not known, but
usually adjusting the dose of medication eliminates the problem.
Another common side effect is an increase in thirst and appetite. The increase in
thirst will be accompanied by a need to get outside more often to get rid of the excess
water. Due to the appetite stimulation, some epileptics will become obese if allowed to.
DON'T LET THEM!! We need to watch their weight and control their diet to keep the weight
reasonable. Obesity creates stress on the heart and other organs in dogs, just like it
would in people, and an epileptic doesn't need extra stress on their body.
Because we usually need to treat the epilepsy for life, we need to monitor for
potentially serious effects of the drugs. Such serious side effects are uncommon, and by
watching for them we can often see them coming in time to avoid them. Of most concern is
the potential for liver or bone marrow damage by some of the drugs. We recommend
performing liver function tests (such as bile acids or ammonia) and blood counts at least
once a year, often more frequently.
Monitoring blood levels
Antiepileptic drugs are not "one size fits all" medications. We need to
optimize the treatment for your companion's individual needs. There are many things that
influence how much of the medication we give the dog is actually available to do the job.
By measuring the actual levels of the drug in the blood, we can better fine-tune our
treatment to best control the seizures. This is particularly important when we first start
the medication or if we are having difficulties with too many seizures or side effects.
Even when the seizures are controlled, it is best to measure levels regularly so we have a
baseline to compare to and can anticipate problems.
Even when a drug is given regularly, there is a bit a see-saw
effect on the levels in the blood. Immediately after we give the medication, the level in
the blood climbs as the drug is absorbed. Once it's all absorbed, the level in the blood
gradually falls as the drug is eliminated from the body. The dose is timed so that there
is always enough medication in the blood (and hence the brain) to control the seizures.
Ideally, the dog's blood levels of medication will fall with the range of levels known to
work without causing too many side effects. This is called the therapeutic range. When
measuring blood levels, we are usually concerned that the level may get too low and allow
the dog to seizure. Thus your veterinarian may recommend that you bring your pet in first
thing in the morning or last thing in the evening, right before they're due for their next
dose. This allows them to measure the lowest, or trough, level. By measuring trough blood
levels, your veterinarian can give you the best advice on how to get the maximum benefit
from the medication. Fasting your pet overnight before the blood tests will prevent fat in
the blood from interfering with the accuracy of the tests. If you have a toy breed dog
that is prone to low blood sugar, a diabetic, or other reasons why fasting might create
problems for your pet, consult your veterinarian first.
"Alternative" therapies
People have sought to
help their pets with their ailments since ancient times, but we have learned much since
those times. |
Epilepsy can be a frustrating disease since in a few cases
available therapies don't work well or have adverse side effects. This can lead owners to
search for alternatives which might better help their pet. These may include treatments
such as acupuncture, herbal remedies, homeopathic preparations or magnets. In the words of
one philsopher, "there are only two types of therapies: those that work and those
that don't." Labeling a therapy as "alternative" or
"conventional", "homeopathic" or "allopathic" only sidesteps
the real question: Does it work?
Epilepsy can be a highly variable disease. We routinely see epileptics who appear well
controlled suddenly have a terrible month and conversely see epileptics who have been
chronic problems suddenly smooth out and do well for a while. Such variability makes it
easy to be fooled into thinking that a treatment is working or not working if we take too
narrow or short term look at a therapy.
As a case in point, we recently evaluated a new treatment for epilepsy that theory and
experimental studies suggested might be a good treatment. One of the first dogs we tried
it on was a Labrador Retriever who was having severe seizures in spite of everything we'd
tried before. The dog went 6 months without a seizure and we thought we were on to
something. So we tried the treatment on more dogs. It failed miserably from then on out,
including the first dog who did so well initially. We can't say why it seemed to work
initially, but it was clear by looking at a number of dogs over a period of time, that it
wasn't a therapy that worked. Thus the only way to say if a therapy is truly effective or
not is to conduct a clinical trial and objectively see how it performs.
Most promotions for alternative therapies rely on testimonials; a few people's stories
of how the therapy worked for them. This sort of approach leaves important questions
unanswered.
· How was
the initial diagnosis established? We've had people bring in everything from cats in heat
to dogs with ear infections and say their pet was having seizures when really something
else was going on.
· What
criteria was used for "success"? If the dog only went a month or two seizure
free, that may just be the natural variation of the disease and not an effect of the
treatment.
· How many
animals were treated and didn't respond? This critical piece of information is always
conveniently overlooked in testimonial promotions. They quote the owners of that Labrador
when he was doing well and forget the other 12 cases that did not succeed.
· How was
the "placebo effect" controlled? People want to believe that the new therapy
will be the answer for their pet. Thus even if the treatment is a placebo (a sugar pill or
some other treatment that has no real effect), you typically see up to 30% of the animals
improve. This is simply because we want to believe in the new treatment, and that colors
how we look at the results. This is especially true if there is no firm measure of success
established, and we rely on a subjective impression of whether the seizures are getting
better or not.
"There must be something to
this ancient wisdom"
The herbalist lore began with people's attempts to treat disease with the tools
available. Much of our modern knowledge of therapy evolved from these treatments. It was
clear that willow bark (aspirin) relieved pain, that foxglove (digitalis) helped heart
disease, or that ma huang (ephedrine) relieved congestion. People attempted to explain
these observations based on the knowledge of the time and developed theories that the
shape of the plant somehow determined what effect it would have or that the treatment
altered the flow of some unseen energy or "humor".
Much of this ancient wisdom was, however, founded on ideas that had little basis in
fact. Keep in mind that the same ancient wisdom that discovered ephedrine also maintains
that rhinoceros horn cures impotence, pushing that species ever closer to extinction. The
same ancient wisdom that discovered digitalis also maintained that blood letting was good
for just about anything. After a while, people began to realize that blood letting was
usually doing more harm than good, and to question why aspirin helped pain and why
digitalis helped heart failure. The result was modern medicine where therapy is based on
understanding as best we can what is really happening to the body in a disease and doing
what we can to maintain health.
That understanding doesn't come easy. It is simpler to fall victim to wishful thinking
that there is something mystical to these herbs and treatments that we don't need to
understand. Still, we can use what was truly wise from these ancient treatments without
turning our backs on the more recent wisdom.
An open-minded clinician doesn't reject a new approach to a problem just because it is
different, but a wise clinician does not accept a new approach just because it is
different. Some unconventional approaches (e.g. the ketogenic diet) are based on sound
reasoning and show promise. There is ongoing research into herbal remedies to see if there
are truly active compounds in the plants which could help. In general, whenever someone
claims to have a new therapy of any kind for epilepsy, be it conventional or not, we take
the Missouri philosophy - "Show me!"
"If it's natural, it must be
safe"
Sassafras makes a delicious tea and was recommended as a tonic for a number of
ailments. Trouble is, one of the major ingredients in sassafras causes liver cancer in
rats. We tend to think of toxins as industrial chemicals, but plants were the original
toxin factories. They produce a wide array of toxins either to protect themselves from
being eaten, or simply as a byproduct of their everyday living. There is no way to know
that this danger exists from looking at the plant, or tasting it, or even seeing what
happens to someone who's just drunk sassafras tea. Only by scientific studies was it shown
that this danger lurks beneath the sweet taste of sassafras. Granted, people aren't rats,
but would you want to bet your liver that we're that much different?
Digitalis was long the mainstay of treating heart conditions, but it wasn't easy. There
was a fine line between enough digitalis to help the heart and too much which could kill
the patient. Many things can influence how much digitalis is in a foxglove extract. The
potency was influenced by everything from the stage of growth when harvested, the weather
conditions during growing, and the amount of insect damage the plant suffered; to the way
the extract was prepared, and how long it has been stored. Thus extreme care had to be
taken to ensure that the amount of digitalis that was given was indeed what we wanted. By
looking at how digitalis both helped and hurt, we've been able to develop new drugs which
can improve heart disease without some of the risks inherent to digitalis.
While some herbal preparations may be completely harmless, if they truly have effects
on the body, there may also be harmful side effects. Drugs are only approved by the Food
and Drug Administration after safety studies have established what side effects might be
expected from the drug. Such studies are not done for "alternative" therapies
and there is no guarantee that they will be safe. We recently saw an epileptic dog who was
being treated with an herbal preparation which contained bella donna extract. The active
drug in bella donna is scopalamine which has been evaluated by the FDA and shown to cause
seizures! Not exactly a wise treatment for an epileptic.
Some alternative therapies, such as acupuncture, massage or magnets, have little
potential to do harm in and of themselves. The danger lies in being lulled into rejecting
a more rational approach to treating the problem. We tend to take modern medicine for
granted and when the seizures finally abate, assume it was the acupuncture rather than the
phenobarbital that was also used.
So be skeptical of claims for success with epilepsy treatments. Any treatments we
recommend for our patients are backed by studies proving their effectiveness and carefully
assessing their side effects. Don't settle for anything less.
Living with an
epileptic pet
Most importantly, LIVE
Epileptic pets can
lead happy, fulfilling lives. |
Do what's enjoyable; all the things that make anyone keep a pet.
You may need to make some adjustments to avoid dangerous situations, but go have fun with
your companion! Concentrate on the time your pet is happy and doing well, rather than
dwelling on the small percentage of time when there are problems.
Most epileptics pets can live relatively normal lives. We can successfully control
epilepsy in over 2/3 of the cases. These dogs may require daily medication, but they can
still run and play and love. Even the best controlled epileptic will still have some
seizures, but usually we can keep their occurrence down to a tolerable level. The number
of dogs who have serious side effects from the medications is very small. Some may
experience sedation, but this does not prevent them from being loving companions. They
don't need to stay awake in class or behind the wheel, so if they need an extra nap in the
afternoon, who cares!
Unless the seizures are due to low blood sugar or heart disease, there is no reason to
restrict exercise in your pet with epilepsy. While swimming carries some risk of drowning
should the dog have a seizure while in the water, most seizures occur when the pet is
relaxed and quiet or sleeping. Thus the odds of having a seizure while swimming are pretty
remote. Canine life vests are also an option.
An epileptic needs a high quality, balanced diet. Any top quality commercial dog food
will supply the needs of your pet. Diets based largely on table food or less expensive
commercial foods may require supplementation to maintain optimum health in your pet.
Consult your veterinarian for specific recommendations.
Keep records of seizures
Accurate records will
help your veterinarian judge the effectiveness of the therapy. |
Keep a notebook or a calendar where your family can record when
your pet has seizures. The goal of therapy is to reduce the number and severity of the
seizures. The only way we can judge whether we are reaching those goals is if we know how
frequent and how bad the seizures have been. Relying on memory isn't sufficient since it
might be six months from now when we're deciding how to alter the medication. Write things
down as they occur.
Be conscientious about treating
Treating epilepsy isn't like treating many other conditions. Missing a dose or two of
the medication could have dire consequences. Be sure you have a routine for giving the
medication and know who's responsible for giving it. If more than one person in the family
may be giving the medication, use a "weekly pill box". These are plastic boxes
available at your pharmacy which contain a compartment for each day of the week. Simply
load the week's medication in the compartments and then you will know if the medication
has been given or not. When you go out of town, be sure the boarding kennel or pet-sitter
knows how to give the medication properly. Plan ahead so that you never run out of
medication. You don't want to be down to one pill on a Saturday night and be frantically
trying to get the prescription refilled on Sunday morning.
Occassionally your pet may vomit right after receiving the medication. We generally
recommend waiting a while so that they don't just vomit again, and then giving the
medication again. Usually we are more concerned about them missing a dose than we are
about giving a double dose. If in doubt about whether to repeat the medication or not,
consult your veterinarian. Vomiting can also be a side effect of the medication, so
consult your veterinarian if the vomiting continues. If your pet is unable to keep things
down, they may need to get injections of their antiepileptic drugs to keep from having
seizures.
When you come for a recheck
Recheck visits are
required to monitor the pet's progress |
Regular rechecks are essential to succesfully treat epilepsy. At
the very minimum, your veterinarian will need to evaluate your pet once a year. More
commonly, two or more rechecks a year are needed. We can do our best for your pet if you
prepare for your appointment. Here are some things you can do to help.
· Hold them
off food that morning. If blood tests are performed, they will be more meaningful if the
pet has been fasted. If your pet is a toy breed with low blood sugar problems, a diabetic,
or has other problems which might make fasting dangerous, consult your veterinarian first.
· Schedule
the appointment so we can measure trough blood levels. Sometimes we will see them first
thing in the morning and give their medication immediately after the blood is taken. Other
times we will schedule them late in the day and get the blood before the evening dose.
· Bring
your records. Your veterinarian will need to know how the pet has been doing to decide
whether adjustments in medication are necessary.
People often worry about how their pet will live with the
disease and how bad the side effects of medication may be. Share with us your story ...
Tell us about your life with a successfully controlled epileptic pet in the CEN Discussion Forum.
What do you do if
your pet has a seizure?
DON'T PANIC!
Most seizures will be very brief. They may seem to go on forever, but the average
seizure lasts less than 2 minutes. Looking at a clock and timing approximately how long
the seizure lasts will be helpful. By observing exactly what your pet does during the
seizure, you may be able to provide your veterinarian or the neurologist with important
clues to what is going on, so watch carefully. Make certain the dog is safe, that they
won't fall down stairs, bang into a sharp edge on the furniture, get tangled in an
electric cord, or otherwise injure themselves. They will NOT SWALLOW THEIR TONGUE. They
will frequently chomp their jaws so if you try to pull the tongue out either you or their
tongue is likely to be bitten. KEEP YOUR HANDS AWAY FROM THEIR MOUTH.
Your veterinarian may recommend giving diazepam (either rectally or orally) or extra
oral phenobarbital if the dog seizes. If giving oral medication, first be sure the dog is
awake enough to swallow and aware enough to not bite. Often they will be hungry
immediately after a seizure and adding the medicine to a ball of food can be an effective
way to give it. If lower blood sugar is suspected as a cause of the seizure, your
veterinarian may recommend giving some honey or corn syrup to bring the blood sugar up
quickly.
The altered behavior following a seizure ( post-ictal behavior) can often be
as disturbing as the seizure itself. Most dogs will appear disoriented and blind for a
period up to several hours after the seizure. Usually just leaving the pet alone and
ensuring that they won't injure themselves until they get back to reality is the best
approach. Sometimes reassuring words and petting can calm them; other times they are
oblivious to our attempts to help. Rarely dogs can become irritable during the post-ictal
phase. If your dog is very agitated or irritable, be careful, especially if children are
involved, since the dog may snap even if they normally wouldn't do such a thing. Don't
attempt to hug or hold them still if they are behaving this way.
When do you seek immediate care?
If your pet has a seizure that has lasted more than 5-10 minutes without stop, they
need to be seen by a veterinarian immediately. Within 30 minutes of continuous seizing,
the risk of brain damage skyrockets, and it will take time to get to your veterinarian or
the emergency clinic. Don't confuse the post-ictal behavior (blindness, pacing, agitation,
etc.) with the seizure itself. The post-ictal behavior can frequently continue for hours.
If the post-ictal behavior is prolonged or severe (for example the animal is at risk for
hurting themselves or behaving aggressively), it may be worth a trip to the veterinarian
even though they aren't actively seizing.
Repeated seizures can also be dangerous. Clusters of seizures have a tendency to
progress to continuous seizures (status epilepticus). If you pet has 3 or more seizures in
a day, they also need to be seen immediately.
Plan ahead
If your dog begins to seize, know what you need
to do so that both of you are safe.
· Will you
need to close a door to a stairway or room that could be hazardous? Move furniture, unplug
lamps, or remove items that could fall over?
· Will
other pets need to be restrained or shut out of the area? Sometimes other pets will be
confused and can act aggressively toward the seizing pet, so it may be best to remove them
when a seizure starts.
· If your
veterinarian has prescribed rectal diazepam or other emergency-use drugs, do you know
where they are and how to administer them even under the stress of a seizure?
· Where is
the phone number for your veterinarian and/or the nearest emergency clinic? What is the
best route to get there and how long will it take? Don't speed or otherwise violate
traffic laws; you won't be able to help your companion if you are in the hospital from an
automobile accident.
· If you
need to transport a seizing or unconscious dog, how will you do it safely? For large
breeds, how will you carry them from the house or yard and load them into the vehicle?
Since your pet may seize again or be in the post-ictal disorientation while you're
transporting them, both you and your pet will be safest if the pet is in an airline crate.
· It may be
a good idea to have a "seizure drill" while everything is calm to be sure things
are manageable if a seizure begins. You will be calmer, more confident, and better able to
help your pet if you know what to do and where things are.
More questions?
Talk to your veterinarian. They should be able to answer other questions you may have
or point you toward addition sources of information.
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