When
to start treatment
There
are no hard and fast rules about when treatment should begin.
Once anticonvulsant therapy has started it is likely that it
will need to be continued life-long. However, there is evidence
that better long-term control of epilepsy is achieved following
early treatment. The big question is therefore when to start
treatment?
Anticonvulsant
treatment
is indicated when:
• |
The
first seizure is life-threatening
(status epilepticus or severe
cluster). |
• |
Multiple
seizures are observed
in a short period of time. |
• |
Seizures
occur more than once a
month and /or the owner finds the
frequency distressing. |
• |
The
seizures are becoming
more frequent or more severe. |
• |
An
underlying progressive disorder
has been identified as the cause of
the seizures. |
• |
Post-ictal
signs are
objectionable (eg aggression). |
|
Image:
Treatment should be started if an underlying progressive
disorder has been identified as the cause of the seizures.
In this dog the adversive posture was associated with
a forebrain lesion - courtesy of Laurent Garosi,
Davies Veterinary Specialists. |
First-line
anticonvulsant drug treatment
The
ideal anticonvulsant drug can be given once daily, is cheap
and has few side-effects. A wide range of drugs are available
for the control of human epilepsy but few of these are effective
in dogs due to altered pharmacokinetics. The most commonly
used anticonvulsants in dogs are: phenobarbitone and bromide.
Primidone is not recommended for the treatment of seizures
in dogs or cats for a number of reasons:
| 1) |
it
is rapidly metabolised by the liver into phenobarbitone
and PEMA |
| 2) |
it is phenobarbitone that is responsible for more than 85% of primidone’s
anticonvulsant effect |
| 3) |
primidone
is more expensive than phenobarbitone |
| 4) |
it
is less well tolerated, particularly with regard to its
potential hepatotoxicity |
Dogs
receiving primidone can be safely converted to phenobarbitone
treatment with no loss of anticonvulsant effect. It is generally
safe to simply swap animals from primidone to phenobarbitone
(250 mg of primidone is approximately equivalent to 60 mg of
phenobarbitone). Alternatively conversion may be done gradually
over 2-3 weeks.
Withdrawal
of anticonvulsants
If
the patient has been seizure free for a year drug withdrawal
may be considered. Before withdrawing the drug therapy weigh
up the pros (potential reduction in side effects and cost)
and cons (potential seizure recurrence). Drug doses must be
tapered slowly and withdrawal should take around 6 – 12
months to complete.
Information
and guides for owners
The
following downloads should answer many of the most common questions
asked by your client.
| Owner
Documents |
 |
About
epilepsy |
ver.060104 |
|
Living
with an epileptic dog |
ver.060104 |
Treament
aids
Please
feel free to download and print the following documents which
you may find useful.
| Owner
Documents |
|
Owner
Questionnaire |
ver.060104 |
|
History checklist for seizuring dog |
ver.060104 |
|
Seizure
Diary |
ver.060104 |
References
Bagley
RS, Harrington ML, Moore MP (1996) Surgical treatments
for seizure: Adaptability for dogs. Vet
Clin North Am Small Anim Pract 26, 827-842.
- PubMed -
Dyer
KR, Shell LG (1993) Anticonvulsant therapy: a practical
guide to medical management of epilepsy in pets. Vet
Med 88, 647-653.
Jacobs
G, Calvert C, Kaufman A (1998) Neutropenia and thrombocytopenia
in three dogs treated with anticonvulsants. JAVMA 212,
681-684.
- PubMed–
Kantrowitz
LB, Peterson ME, Trepanier LA et al (1999) Serum total
thyroxine, total triiodothyronine, free thyroxine, and thyrotropin
concentrations in epileptic dogs treated with anticonvulsants. JAVMA 214,
1804-1808.
- PubMed -
Platt
SR, McDonnell JJ (2000) Status epilepticus: Patient
management and pharmacologic therapy. Compendium on
Continuing Education for the Practicing Veterinarian 22(8),
722-729.
- Compendium -
Podell
M, Wagner SO, Sama RA (1998) Lorazepam concentrations
in plasma following its
intravenous and rectal administration in dogs. J Vet
Pharmacol Therap 2, 158-160.
- PubMed - |
