SEIZURES IN DOGS
Seizures are one of the most
frequently seen neurological problems in dogs. A seizure is also known as a convulsion or
fit. It may have all or any combination of the following:
Loss or derangement of consciousness
Contractions of all the muscles in
the body
Changes in mental awareness from
non-responsiveness to hallucinations
Involuntary urination, defecation,
or salivation
Behavioral changes, including
non-recognition of owner, viciousness, pacing, and running in circles
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Pre-ictal phase
The pre-ictal phase, or aura, is a period of
altered behavior in which the dog may hide, appear nervous, or seek out the owner. It may
be restless, nervous, whining, shaking, or salivating. This may last a few seconds to a
few hours.
Ictal phase
The ictal phase is the seizure itself and lasts
from a few seconds to about 5 minutes. During this period, all of the muscles of the body
contract strongly. The dog usually falls on its side and seems paralyzed while shaking.
The head will be drawn backward. Urination, defecation, and salivation often occur. If it
is not over within 5 minutes, the dog is said to be in status epilepticus or prolonged
seizure.
Post-ictal
During the post-ictal phase, there is confusion,
disorientation, salivation, pacing, restlessness, and/or temporary blindness. There is no
direct correlation between the severity of the seizure and the duration of this phase.
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Despite the dramatic signs of a
seizure, the dog feels no pain, only bewilderment. Dogs do not swallow their tongues. If
you put your fingers into its mouth, you will do no benefit to your pet and will run a
high risk of being bitten very badly. The important thing is to keep the dog from falling
and hurting itself. As long as it is on the floor or ground, there is little chance of
harm occurring. If seizures continue for longer than a few minutes, the body temperature
begins to rise. If hyperthermia develops secondary to a seizure, another set of problems
may have to be addressed.
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There are many, many causes of
seizures. Epilepsy is the most common and of least consequence to the dog. The other
extreme includes severe diseases such as brain tumors. Fortunately, most are due to
epilepsy.
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Now that the seizure is over, can anything be done to understand why it happened?
When a seizure occurs, we begin by
taking a thorough history concentrating on possible exposure to poisonous or
hallucinogenic substances or history of head trauma. We also perform a physical
examination, a basic battery of blood tests, and an electrocardiogram (EKG). These tests
rule out disorders of the liver, kidneys, heart, electrolytes, and blood sugar level.
If these tests are normal and there
is no exposure to poison or recent trauma, further diagnostics may be performed depending
on the severity and frequency of the seizures. Occasional seizures are of less concern
than when the seizures are becoming more severe and frequent. In this instance, a spinal
fluid tap and fluid analysis may be performed. Depending on availability, specialized
imaging of the head MRI may be performed. Fortunately, these additional tests are usually
not needed.
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Treatment is determined by how long
it takes for another seizure to occur. That may be days, months, or years. At some point,
many dogs have seizures frequently enough to justify continuous anticonvulsant therapy.
Since that means that medication must be given every 12 to 24 hours for the rest of the
dog's life, we do not recommend that until seizures occur about every 30 days or unless
they last more than 5 minutes.
It is important to avoid sudden
discontinuation of any anticonvulsant medication. Even normal dogs may be induced to
seizure if placed on anticonvulsant medication and then abruptly withdrawn from it. If
there are no seizures for a significant period of time we can try to decrease and if
possible even discontinuing the medication. This should only be done with veterinary
supervision.
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Status epilepticus bears special
note. It is characterized by a seizure that lasts more than 5 minutes. When it occurs, the
dog's life is endangered. Unless intravenous medication is given promptly, the patient may
die. If this occurs, you should seek emergency treatment by a veterinarian immediately.
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