Overview
Idiopathic epilepsy is a specific term referring to a seizure
disorder that has no identifiable cause. It is also referred to as genetic or
congenital epilepsy. The terms epilepsy, seizure, fit or convulsion all mean the
same thing, the physical manifestation of a sudden, excessive electrical discharge
of neurons in the brain that results in a series of involuntary contractions of the
voluntary muscles, abnormal sensations, abnormal behaviors, or some combination of
these events.
In your pet, the physical manifestation can vary between a far-away look or
twitching in one part of the face to your pet falling on his side, barking, gnashing
his teeth, urinating, defecating and paddling his limbs.
Seizures usually appear suddenly and end spontaneously, and can last from seconds
to minutes. Idiopathic epilepsy can occur in all pedigree breeds as well as mixed-breed
dogs. In some breeds, idiopathic epilepsy has been proven to be genetic. These breeds
include German shepherd dogs, keeshonds, Belgian tervurens, beagles, Irish setters,
Saint Bernards, poodles, wirehaired fox terriers, cocker spaniels, Labrador retrievers
and golden retrievers.
Because idiopathic epilepsy or a predisposition to epilepsy might be inherited,
neither epileptic animals nor their first-degree relative should be used for
breeding.
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Components of a Seizure
There are three components of a seizure:
- Aura: Certain signs of an impending seizure may
be evident, such as restlessness, whining, shaking, salivation, affection, wandering
or hiding. These signs may persist from seconds to days in duration and may or may
not be apparent to you.
- Ictus: During ictus, the seizure occurs. The attack
may last seconds or minutes. Your dog may fall on his side and may look like he is
kicking or paddling. He will salivate, lose control of his bladder, and be unaware
of his surroundings.
- Postictial stage: This stage occurs immediately after
the seizure. Your dog will appear confused and disoriented and may wander or pace. He
may still exhibit salivation and may be unresponsive to you. Or he may come to you for
comfort. The period may be short or it may last for days.
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What to Do If Your Pet Has a Seizure:
- Do not panic. If your pet is having a seizure, he is unconscious
and he is not suffering. Your pet may seem like he is not breathing, but he is.
- Time the seizure. Actually look at a clock or watch and note the
time; although it may seem like forever, it may only be 30 seconds.
- Keep your pet from hurting himself by moving furniture away from
the immediate area. Also protect him from water, stairs, and other sharp objects. If
possible, place a pillow under his head to prevent head trauma.
- Note what type of muscular activity or abnormal behavior does
your pet exhibits during the seizures? Your veterinarian may want you to keep a record
of the date and length of time of each seizure.
- If the seizure lasts more than 5 minutes, call your veterinarian
or veterinary emergency clinic immediately.
- Pets do not swallow their tongues. Do not put your hand in your
dog's mouth - you may get bitten. Do not put spoons or any other object into your pet's
mouth.
- Keep children and other pets away from your seizing
animal.
- Remain by your pet's side; stroke and comfort your animal so
when he comes out of the seizure you are there to calm him.
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After the Seizure
- Observe your pet's post-seizure behavior. Do not allow your
pet access to the stairs until he is fully recovered. Offer water if he wishes to
drink.
- Be prepared for vocalization and stumbling after the seizure
ends. You need to be strong and offer support and comfort to your pet. He will be
confused and may feel as though he did something wrong. Speak softly and with a soothing
voice.
- If your pet has not fully recovered within 30 minutes, contact
your veterinarian or local emergency facility.
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Signs That Require Emergency Veterinary Attention
- Seizures that last longer than 10 minutes
- Seizures that occur more than 2 times in a 24 hour time
period
- Seizures that begin before your pet has completely recovered
from the previous seizure
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Diagnosis
By definition, idiopathic epilepsy is a seizure disorder with no
known cause, however it is important for your veterinarian to determine your pet's
general health and make sure there is no underlying disease that may be causing the
seizures. Your veterinarian will take a detailed history and perform a complete physical
and neurological examination. Recommended blood tests may include a CBC, serum
biochemistry panel, toxin screen, urinalysis and fecal examination.
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Treatment
The goal of treatment is to reduce the severity and frequency of
the seizures while avoiding unacceptable side-effects. It is rare to completely eliminate
all seizures in dogs with idiopathic epilepsy. your veterinarian may choose to treat the
disorder with anticonvulsant medications.
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Drug Therapy
- Phenobarbital is usually the drug of first choice for idiopathic
epilepsy. It is given two to three times a day by mouth at an initial dose of 1 mg per
pound twice a day.
- The other common anti-convulsant used in dogs is oral diazepam>
or valium.
- Bromide is the active ingredient in potassium bromide and sodium
bromide and is another anticonvulsant that can be used in addition to phenobarbital or
as an initial monotherapy drug. Many dogs that do not initially respond to phenobarbital
alone will have a dramatic decrease in seizure frequency and severity with the addition
of bromide.
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Home Care
At home, follow your veterinarian's recommendations regarding
drug administration and monitoring, and maintain a complete seizure log with information
regarding the seizures, any medication change, veterinary visits and illnesses.
Haphazard drug administration or abrupt changes in medication may be worse than no
treatment at all and may cause status epilepticus, a condition characterized by persistent
seizure activity for a period of more than 30 minutes or repeated episodes of seizure
activity without recovery in between.
Blood tests will be required to monitor your dog's response to therapy and guard against
toxic effects from the seizures as well as the anti-convulsants.
The diagnosis of idiopathic epilepsy is not a death-warrant; epilepsy is a chronic disease
that can be managed in the vast majority of cases. There is help for you and your dog. Work
with a veterinarian with whom you feel a good rapport. Educate yourself on seizures and
their treatment.
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Information In-depth
Epilepsy is a condition characterized by recurrent seizures.
Approximately 2 to 3 percent of dogs are epileptic and the age at which dogs with
idiopathic epilepsy have their first seizure is usually between 1 and 5 years of age.
Many pets can have one seizure without ever having a second. The seizures can be generalized
or partial.
Partial or focal seizures indicate activation of a limited number or group of neurons.
Generalized seizures indicate a synchronous discharge of a large number of neurons in both
sides of the brain. The majority of dogs (50 to 60 percent) with idiopathic epilepsy have
generalized seizures.
Seizures usually appear suddenly and end spontaneously. Seizures can last from seconds to
minutes. Generalized seizures that last more than 30 minutes or multiple seizures that occur
so rapidly as to prevent complete recovery are considered emergency situations that require
immediate intervention as permanent brain damage may occur after this 30 minutes.
Some dogs exhibit the following three stages of seizures. However, not all dogs have
the exact type of seizure stages.
- The aura or prodromal stage is the time immediately before
the actual seizure, which may last minutes or hours. During this time, your dog may
show a slight change in behavior or attitude. In many dogs, the seizures begin suddenly
without any warning signs.
- The ictus is the actual seizure episode in which your dog may
become stiff, lose consciousness, fall over and begin paddling, vocalize, gnash the
teeth, urinate, defecate, and salivate. This stage can last seconds to minutes and is
generally the part of the seizure your veterinarian wants you to time. During this time,
your dog is unconscious and is not suffering.
- The post-ictal phase immediately follows the ictus and begins
as your dog regains consciousness, as evidenced by looking around or focusing on
something or someone. Some dogs remain lying down in exhaustion or fall into a deep
sleep. Some stand up after a few seconds or minutes. They may be disoriented, weak,
poorly responsive, blind, deaf and/or anxious. Most dogs return to normal within a few
minutes although some dogs may require days to recover completely.
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Several different diseases may cause seizures (convulsions). The
term idiopathic epilepsy refers to a seizure disorder the cause of which remains unknown
despite a thorough diagnostic evaluation. Treatment and prognosis (outcome) of seizures
depend on their underlying causes. The following are the most significant causes of
seizures in dogs and cats:
- Structural disorders
- Viral or inflammatory disorders
- Distemper
- Fungal disease (e.g. cryptococcosis)
- Toxoplasmosis
- Encephalitis
- Rabies
- Brain abscess
- Head trauma
- Brain tumor
- Cerebral infarct (uncommon in dogs and cats)
- Vasculitis (inflammation of blood vessel)
- Developmental disorders (e.g. hydrocephalus)
- Metabolic Disorders
- Hypoglycemia (low blood sugar)
- Hepatoencephalopathy (liver disease)
- Advanced uremia (kidney failure)
- Pocalcemia (low blood calcium concentration)
- Hypernatremia (high blood sodium concentration)
- Hypoxia (low blood oxygen)
- Thiamine deficiency (B-complex vitamin deficiency)
- Poisoning
- Antifreeze
- Lead
- Organophosphates
- Carbamates
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Veterinary Care In-depth
Veterinary care should include diagnostic tests and subsequent
treatment recommendations.
Diagnosis In-depth
Your veterinarian will take a detailed history regarding the seizure
episodes including any information about the seizure, the breeding or litter history,
toxin exposure and their previous health record.
Your veterinarian will perform a complete physical and neurological examination.
By definition, idiopathic epilepsy is a seizure disorder with no known cause, although it
is important for your veterinarian to determine your pet's general health and make sure
there is no underlying disease that may be causing the seizures. Recommended blood tests
may include:
- A complete blood count (CBC or hemogram) to check blood
counts
- Serum biochemistry tests to evaluate blood glucose, electrolyte
and protein concentrations
- Bile acid determinations to evaluate liver function
- Urinalysis to assess kidney function
- Fecal examination to check for parasites
Based upon the presentation, age, breed, seizure episode and results
of the above tests a diagnosis of idiopathic epilepsy may be made and treatment may be
recommended.
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Treatment In-depth
- The most overlooked aspect of treatment is keeping a seizure log
in which you write down exactly when (time and day) your dog has a seizure, including the
total length of the seizure and any predisposing activities that you remember. Note what your
dog does during the seizure. If you suspect your dog had a seizure but you did not witness it,
list it as a question mark in your seizure log.
- Treatment is indicated for idiopathic epileptics depending on the
severity and time between seizures. Generally, medical treatment is generally advised for
animals who have one or more seizures every six weeks. Dogs who have cluster seizures or go
into status epilepticus (more than one seizure in a 24-hour period) may be treated even
though the time between seizures is greater than six weeks.
- If you and your veterinarian decide to treat your dog with an
anticonvulsant, you must make a commitment to giving the medications exactly as prescribed
with absolutely no changes in the dose or drug without veterinary consultation. Haphazard
drug administration or abrupt changes in medication may be worse than no treatment at all
and may cause status epilepticus.
- The goal of treatment is to reduce the severity and the frequency of
the seizures while avoiding unacceptable side-effects. It is rare to eliminate completely
all seizures in dogs with idiopathic epilepsy.
- Phenobarbital is usually the drug of first choice for idiopathic
epilepsy. It is usually effective in more than 80 percent of the cases when administered
at the correct dose and frequency. It is given two to three times a day. During the initial
treatment period of 10 to 14 days, side effects are usually seen with this drug consisting
of excessive drinking, urinating and eating. Some dogs may act very lethargic as well. These
side-effects are temporary and diminish two weeks after initiating treatment.
- Phenobarbital comes in 15, 30, 60 and 100 mg tablets. Phenobarbital
tablets are often referred to according to grains (gr.). For reference 1 grain equals 60 mg.
There is also a syrup or elixir available.
- Blood phenobarbital concentrations should be measured two weeks after
any change in dose or if there is a change in seizures frequency or severity. Concentrations
are determined by drawing blood. The level of drug needed to control seizures varies between
individual dogs but generally should be above 25 ug/dl before treatment is considered
failed.
- Dogs can have liver problems with chronic, high-dose phenobarbital
treatment. Regular annual or semi-annual blood tests may be recommended to evaluate your
dog's liver function.
- The other common anti-convulsant used in dogs is oral diazepam or
valium given three times a day.
- Bromide is the active ingredient in potassium bromide and sodium
bromide and is another anticonvulsant that can be used in addition to phenobarbital or as
an initial drug. Many dogs that do not initially respond to phenobarbital alone will have
a dramatic decrease in seizure frequency and severity with the addition of bromide.
Bromide is the drug of choice for animals with liver disease. Bromide is always given on a
full stomach. Giving bromide on an empty stomach can cause vomiting. Bromide is not approved
for use in dogs, nor is it commercially available at this time. Bromide can be given as a
capsule or dissolved in water or as syrup.
Bromide has an extremely long half-life which means it can be given once a day. It also
takes 6 to 8 weeks to reach therapeutic levels in the blood unless your veterinarian
recommends giving a loading dose. Side-effects from the bromide include increased eating,
drinking, urinating and incoordination. These side-effects are usually temporary but if they
are problematic, a dose reduction in either one of the drugs may be recommended.
- Diazepam (Valium) is used for the treatment of status epilepticus.
Your veterinarian usually gives it in emergency situations by the intravenous (IV) route.
Your veterinarian may recommend diazepam by rectal or nasal administration if your dog has
severe seizures. This is not common situation and requires special training.
- Alternative therapies range from acupuncture to herbs and vitamin
therapies as well as dietary recommendations. Work with your veterinarian in selecting the
right treatment for your dog's seizures.
- Other drugs such as primadone, phenytoin, gabapentin, carbamzaine
and valproic acid are used in certain specific situation as tertiary drugs.
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Follow-up
- Maintain a complete seizure log with information regarding the
seizures, any medication change, veterinary visits and illnesses. Always follow your
veterinarian's recommendations regarding drug administration and monitoring.
- Blood tests will be required to monitor your dog's response to
therapy and guard against toxic effects from the seizures as well as the anti-convulsant
medications.
- The most common reason why treatment for idiopathic epilepsy fails
is the lack of proper administration of drug. Do not change medication dose or frequency
without speaking first to your veterinarian.
- Gastrointestinal or other illnesses may affect drug administration
and influence seizure frequency or severity.
- Be aware that other drugs can affect anti-convulsant drug
distribution. Always ask what the effect any drug may have on your dog's
seizures.
- During a seizure, do not attempt to open your dog's mouth or
manipulate its tongue - you may get bitten inadvertently.
- Protect your dog from injury by moving the animal away from
hazardous objects like furniture with sharp corners or harmful locations like the top
of the stairs.
- Give your dog sufficient time to recover from the seizure. Speak
calmly and try to comfort your dog during a seizure
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