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The account
accompanying my notes was written by the owner of a Beardie
who does not want to be identified. Seizures are scary for
an owner – especially the first time – so I wanted to
include a first hand account.
A seizure is a
symptom and not a diagnosis. It is estimated that about 1%
of dogs will experience a seizure over the course of their
life, and while they are more common in certain breeds
(affecting 15-20% of animals) they are relatively infrequent
in Beardies. A seizure represents a transient paroxysmal
disturbance in the electrical activity of the gray matter,
most often in the cerebral cortex but sometimes in the
thalamus, hypothalamus or midbrain. The appearance of the
seizure can reflect the area of the brain affected. It may
involve changes in behavior, consciousness, muscle activity,
sensation or autonomic (unconscious) actions. Behaviorally
seizures can manifest as confusion, dementia, delirium, rage
or fear. Muscular changes can produce involuntary spasms
that can be rigid (tonic) or jerky (clonic) or result in
limb paddling. The jaw may be locked or the dog may make
chewing, licking or lip smacking motions. The dog may spin,
pace or run if he remains upright. In humans we know that
seizures are often accompanied by sensory changes, but these
are harder to appreciate in dogs. Pawing at the face,
attacking the tail or chewing and biting the flanks may
indicate changes in body sensation. Biting at invisible
flies may be a manifestation of visual hallucination.
Increased sensitivity to sounds, light, and/or touch may be
appreciated, as well as increased sniffing suggesting
increased awareness of smells. Rapid eye movements (nystagmus)
may be noticed along with loss of balance. Increased
salivation along with uncontrolled urination and defecation
represent over-activity of the autonomic nervous system.
Rarely paroxysmal vomiting and diarrhea will be part of the
seizure.
Seizures are
classified as general or partial/focal and can be mild or
severe. In mild general seizures the dog may appear
confused and have muscle tremors – rippling skin/shaking.
He may seek comfort from his owner and reassurance may
actually curtail the seizure. Mild seizures can build into
severe ones, however. Electroencephalograms recorded during
mild seizures show symmetrical alterations in electrical
activity, while in severe ones there is massive electrical
discharge throughout the cortex. Partial seizures show
localized, asymmetrical changes and the symptoms reflect the
part of the brain affected. In the motor cortex there will
be spasms of the face or limbs on the opposite side from the
brain activity. Partial seizures affecting the limbic
system result in outbursts of abnormal behavior – frantic
running, aggression, rage and/or hallucinations.
Seizures can have
many causes. Recurrent seizures of no known cause are
referred to as idiopathic epilepsy. This condition is
usually inherited and is usually first seen when the dog is
between one and three years of age. However, some
“idiopathic” epilepsy is likely the result of trauma to the
brain, with seizures starting 6 to 12 months after the
injury. In dogs under 9 months of age, seizures are often
the result of congenital problems (hydrocephalus,
lissencephaly, storage disorders, metabolic disorders,
portosystemic shunt); infection (distemper and other viral
diseases, fungal, protozoal or bacterial encephalitis);
toxicity (lead, organophosphates); trauma; hypoglycemia;
thiamine deficiency. From 9 months onwards infection,
trauma, toxicity, hypoglycemia, metabolic disorders, and
idiopathic epilepsy are joined as potential causes by
meningoencephalitis, acquired hepatic encephalopathy
(secondary to liver disease); as well as brain cancer in
older animals.
During a seizure
the threshold for excitation in a number of nerve cells in a
region of the brain is lowered either due to an increase in
excitatory neurotransmitters or reduction in inhibitory
ones. (Neurotransmitters are chemicals that transmit
nervous activity from nerve to nerve or from nerve to
muscle.) The activity of nerves is also dependent on the
concentrations of potassium, sodium, calcium and chloride
ions within and outside the nerve. Changes in electrolyte
levels can also result in seizures. The nerve cells at the
focus of the seizure stay excited for a prolonged period and
gradually excite surrounding cells in an increasingly larger
area. This is called kindling. Other foci of activity can
also be established. Once enough neurons are involved the
seizure will be seen. A typical seizure often has three
phases: the pre-ictal or prodromal period – sometimes called
the aura (when the dog may realize that a seizure is coming
and react in a characteristic manner), this can last more
than a day; the ictus (the actual seizure); and the
post-ictal phase (which may include pacing, depression,
drinking, eating or sleeping, but which is characteristic
for each patient) which can continue for several days.
Between seizures most dogs appear totally normal.
Because most dogs
are normal by the time they see a veterinarian, history is
most important in evaluating seizures. A single seizure is
scary to owner and Beardie, but may never happen again, so
apart from watching to see if there are more seizures little
else needs to be done. If a dog suddenly starts having
multiple seizures within a week, it suggests active brain
disease and it would be wise to initiate a more aggressive
diagnostic plan. Partial seizures or partial seizures that
generalize suggest a structural, localized problem –
encephalitis, tumor, injury or stroke. If the owner notices
a characteristic turn of the head, spasms, on one side of
the face or the lifting of one leg before the seizure it
suggests a localized seizure that has generalized.
Asymmetry of the signs also suggests partial versus
generalized seizures. Partial or mild general seizures can
last over 30 minutes, but partial seizures that generalize
or severe general seizures last less than five minutes –
although it can seem like hours! A video of the seizure can
provide important diagnostic information. Changes in
behavior and/or gait between seizures indicate an active
disease process in the brain.
A thorough history
will gather information about the various body systems –
respiratory, gastrointestinal, renal, etc. – which may
indicate a systemic disease altering brain function.
Information on diet; exposure to toxins and drugs; known
traumas; similar signs in other animals in the same
household or in related animals; current medications can all
provide relevant diagnostic data. The physical examination
should include examination of the eyes and a complete
neurological examination. Typically, testing would include
a complete blood count, fasting biochemistry profile,
thyroid profile, bile acids, serum lead and/or
cholinesterase levels (if toxicity is suspected), urinalysis
and if neoplasia is suspected chest and abdominal X-rays.
Hypothyroidism, electrolyte imbalances, metabolic disorders
and/or toxicity must all be ruled out. If the dog is having
frequent seizures, further testing would include MRI or CT
of the brain, EEG and testing of the cerebrospinal fluid to
find the underlying cause.
If the primary
cause of the seizures is discovered treatment is directed at
treating this, although anticonvulsant therapy may be
initiated while it is brought under control, and then
gradually phased out. If a cause cannot be discovered and
seizures occur more frequently than twice a month, or in
clusters, treatment is aimed at reducing frequency to an
acceptable level. The treatment of all underlying causes is
beyond the scope of this article. The drugs most frequently
used to control seizures are phenobarbital and/or potassium
(occasionally sodium) bromide. Phenobarbital is the
cheapest and most effective drug, but it is also toxic to
the liver, and because absorption is variable blood levels
must be carefully monitored – the therapeutic level being
close to the lethal one. Combining the two drugs may allow
lower doses of phenobarbital to be given effectively and
more safely, as bromides have no liver toxicity. Both drugs
– given alone or in combination – can produce a level of
sedation unacceptable to the owner. However, in general,
either alone or in combination these drugs can be used
safely and effectively to control seizures. Diazepam is too
short acting in dogs to be of value in preventing seizures,
but can be given intravenously or rectally to quickly stop
cluster seizures (status epilepticus). If these are
unchecked, loss of oxygen can cause irreparable brain
damage. Newer drugs are also being used to treat some
seizures in dogs. These include gabapentin (Neurontin),
zonisamide (Zonegran) and levetiracetam.
Patients with
seizures should be fed a balanced diet without extra
supplementation. They should avoid chemicals and drugs
which could make them more susceptible to seizures. While
clinical studies are lacking heartworm preventatives
containing ivermectin and flea preventatives Program and
Advantage may lower seizure threshold and make seizures more
difficult to control. Organophosphate insecticides should
be avoided. Interceptor and Frontline appear to be safer
for patients with seizure disorders.
Acupuncture can be
effective in some cases, including those that resist
pharmaceutical intervention. Valerian root is a traditional
anticonvulsant, which may be beneficial and could be tried
before turning to more potentially toxic treatments. Milk
thistle might help to protect the liver during phenobarbital
therapy.
Chances are good
that you and your Beardie will never experience a seizure.
If you do, try to stay calm and not panic.
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The bumping
against the closet doors woke us up at 4:45 am on Tuesday,
May 9, 2006. He was having a generalized seizure. That’s the
term they use now for what we used to call a “grand mal”
seizure. I was terrified. Here was a Beardie lying there
salivating, urinating, paddling, jaw clenched, breathing as
if he were running, but choking at the same time and I had
no idea what to do. This lasted about a minute. Then he
calmed down and the “cool down” period lasted another minute
with his breathing slowing, heart rate slowing and wanting
to get up. We kept him lying down until he appeared to be
back to normal. When he did get up he seemed coherent. I
snapped on his leash and rushed him to the all-night
emergency hospital. Of course, the vet on duty sent me home
to monitor him and make sure he was ok. He was a bit
unsettled and clingy over the course of the morning.
I called my
regular vet the next day and put in a call to my good friend
who is Professor Emeritus of Veterinary Neurology. She
suggested taking him to a nearby teaching hospital for
superficial neurological tests, as well as blood work.
Everything came back “normal”. Meanwhile, my friend gave me
a “Seizure 101” Cliff Notes version of canine seizures that
night on the phone.
The advice was,
just wait and see if he has another one. He recovered just
fine. I spent hours Googling “seizures in dogs” and read
mountains of material. After awhile, the material began to
repeat itself so I felt comfortable that I was reading the
right stuff. And, of course, we scoured the yard to make
sure he had not gotten into any poison or other chemicals
and checked all of our records for yard spraying. Shoot, we
checked everything we could think of and came up empty.
Many things can
cause seizures, and many of those we don’t even know about.
The next seizure
happened in September of that year…Monday, September 4,
2006, 4:00 am-ish as a matter of fact. On the advice of my
friend, I keep a log of each seizure, noting day, date, time
of day, duration of seizure, symptoms, and length of
recovery time. This time, the seizure lasted a little longer
and it was stronger. Evidently, he had thrown up first. In
addition to the above things, he gnashed his teeth and
defecated. His tongue and gums were gray. He had a secondary
seizure that lasted another minute or so, with more
paddling. Afterward, his emotions were out of whack for at
least a couple of hours. Again, he knew the seizure was
coming on because he had come flying into our bedroom at the
onset. I was calmer because I had been through this one time
before.
This time I made
an appointment with a veterinary neurologist who suggested
we put him on Potassium Bromide (KBr) to forestall any
future seizures. In addition we had a battery of blood tests
done, an MRI and joint taps, all of which came back as those
of a healthy dog. So, the decision, give KBr or not? I opted
for the medicine, against my husband’s and, probably, many
others’ wishes. He was on that for a year and was
seizure-free, but the medicine did have side effects, one of
them making him terribly hungry or having a terribly upset
stomach. During the period he was on that medicine, we had
to barricade the kitchen to keep him from climbing on the
counters trying to find food. Luckily, the KBr worked fine
and did not have to be paired with Phenobarbital. Three
months after discontinuing the medicine, he had another
seizure.
Same drill, 5:00
am, came in and jumped on our bed. This was, yet, worse than
the ones he had before. I reported the seizure to all of his
doctors but opted to wait and see before putting him back on
KBr.
The next one came
on Saturday, May 10, 2008, around 4am. Basically, it was the
same as before but not, quite so bad.
The latest seizure
came Friday, September 5, 2008 around 5:30 am. This one
lasted around a minute, with a secondary seizure or, maybe a
cool-down period of a minute and a half. He woke us up
throwing up, and then he jumped on the bed to have the
seizure.
All we can do
during these is steady him and try to keep his throat clear
(by keeping his head and neck straight as possible) so he
can breathe. Until the seizures happen more frequently, he
won’t go back on medicine.
If you notice the
dates, you’ll see that 4 of them have been 2 years apart,
almost to the day.
May 9, 2006
May 10, 1008
September 4, 2006
September 5, 2008
December 12, 2007
Aside from the
December seizure (which was 3 months after going off of his
medicine), that tells me something “otherworldly” is causing
them, something that science has not identified yet. People
will say I’m crazy, that statistically it’s insignificant,
but, to me, it means something. I don’t know what, but
something.
So, we have
decided to live with these until they become more frequent.
I’m going to start acupuncture treatments and just monitor
him, especially around May and September. During all of
this, he was able to continue herding sheep but did have to
stop agility when he first started KBr treatment. As the
amount of KBr tapered off, he was able to resume agility
practice again. In between seizures, we have a perfectly
normal Beardie.
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