Seizures are the result of a
disturbance in the electrical activity of brain cells. They can occur for a
variety of reasons, in any breed of dog. Epilepsy is the term used for recurrent
seizures where no underlying disease process can be identified as the cause
(also called idiopathic epilepsy).
What is idiopathic
Inherited idiopathic epilepsy is genetically transmitted in some breeds of dogs.
Seizures typically begin between 1 and 3 years of age. Before or after this age,
the seizures are more likely caused by an active disease process, such as
infection, trauma, a metabolic disorder, or a tumour.
How is epilepsy inherited?
The mode of inheritance is unknown, and varies between breeds. In some breeds,
it appears that more than 1 gene is involved.
What breeds are affected by epilepsy?
Instances of idiopathic epilepsy have been reported in nearly all breeds.
However there is an increased risk, and evidence for an inherited basis, in the
following breeds: Belgian tervueren (a high incidence), beagle, Bernese mountain
dog, Brittany spaniel, cocker spaniel, collie, German shepherd, golden
retriever, Irish setter, keeshond, Labrador retriever, poodle (all sizes),
miniature schnauzer, Saint Bernard, wirehaired fox terrier
For many breeds and many disorders, the studies to determine the mode of
inheritance or the frequency in the breed have not been carried out, or are
inconclusive. We have listed breeds for which there is a consensus among those
investigating in this field and among veterinary practitioners, that the
condition is significant in this breed.
What does epilepsy mean to your dog & you?
The effects of a seizure depend on the part of the brain involved. Typically
there is a change in behaviour (eg. confusion, fear, rage), consciousness (the
animal may or may not lose consciousness), motor activity (rigid or jerky muscle
spasms, or paddling), and autonomic activity (salivation, urination, and
defecation). Changes in sensory function may lead to pawing at the face, tail
chasing, or biting at part of the body or the air.
Seizures may be partial or generalized, and mild or severe (grand mal). A dog
experiencing a mild generalized seizure might be confused, show weakness and
some muscle tremors, and look to the owner for reassurance. A dog in a grand mal
seizure will be unconscious, with rigid or jerking limbs, and involuntary
salivation, urination, and defecation.
Seizures vary in frequency as well, from very occasional to almost constant.
Status epilepticus is a series of seizures in rapid succession, or 1 continuous
seizure. This is a medical emergency which requires immediate veterinary
It is common for a dog to show a change in behaviour such as hiding or
attention-seeking for hours or even days before a seizure (called the prodrome
or aura). Abnormal behaviour associated with fatigue, depression, hunger,
thirst, or hyperactivity may last for days afterward (post-ictal phase).
How is epilepsy diagnosed?
You may not recognize that what has occurred in your dog is a seizure
(especially if mild), and your dog will likely be back to normal by the time you
see your veterinarian (except in the case of status epilepticus). Thus your
description of the abnormal activity you observed is very important.
In order to determine if seizures are due to an underlying disease or are a
result of idiopathic inherited epilepsy, your veterinarian will consider the age
and breed of your dog and the changes you observed, do various diagnostic tests
to rule out other possible causes, and ask questions such as whether your dog
may have been exposed to any toxins or possibly received a head injury.
The sudden onset of frequent seizures usually indicates an active brain disease,
whereas otherwise normal animals that have a few seizures a year likely have
How is epilepsy treated?
Treatment depends on factors such as the severity and frequency of the seizures.
A dog that experiences the occasional mild seizure probably needs no treatment
other than watchfulness on the part of the owner. Grand mal seizures or status
epilepticus, at the other extreme, require emergency medical treatment to sedate
or anesthetize the dog, and to prevent the brain damage associated with
prolonged seizure activity.
Once your veterinarian has determined that your dog has idiopathic epilepsy (ie.
no specific cause that can be treated), s/he will likely recommend regular
medication to control seizures if they occur more than once a month or in
clusters, or if your dog has experienced a grand mal seizure. Phenobarbital is
the drug most commonly used and it is safe, effective and inexpensive. Your
veterinarian will work with you to determine the lowest effective dose for your
dog. You will be asked to keep careful track of any seizures as well as all
drugs given. Blood levels of phenobarbital should be measured periodically, as
well as indicators of liver and kidney function. With this monitoring, most dogs
with idiopathic epilepsy can lead a normal life. Dosages may need to be adjusted
if there is a change in seizure frequency or severity, or if medication is given
for another reason. If seizures were initially readily controlled and none has
occurred for 6 to 9 months, your veterinarian may very gradually reduce the
dosage, and sometimes ultimately discontinue the use of anticonvulsants.
Phenobarbital is not always effective and there are other anticonvulsants that
can be tried. Acupuncture is another alternative which may be effective as a
first line of treatment, or when use of anticonvulsants fails to control the
seizures. A veterinarian specializing in acupuncture should be consulted.
Dogs that have experienced seizures, and their parents and siblings, should not
be used for breeding.
The Institute for Genetic Disease Control in Animals http://www.vetmed.ucdavis.edu/gdc/gdc.html
maintains an open research database for idiopathic epilepsy in the Irish setter,
Labrador retriever, and Bernese mountain dog. The Keeshond Club in Britain has
operated a genetic counselling programme for keeshonds since 1989. The American
Belgian Tervueren Club has also participated in a programme to gain information
to reduce the incidence of epilepsy in this breed.
FOR MORE INFORMATION ABOUT THIS
DISORDER, PLEASE SEE YOUR VETERINARIAN.
Institute for Genetic Disease Control in Animals: http://www.vetmed.ucdavis.edu/gdc/gdc.html
Hall, S.J.G., Wallace, M.E. 1996. Canine epilepsy: a genetic counselling
programme for keeshonds. Veterinary Record. 138: 358-360.
Chrisman, C.L. 1995. Seizures. In S.J. Ettinger and E.C. Feldman (eds.) Textbook
of Veterinary Internal Medicine, pp. 152-156. W.B. Saunders Co., Toronto.
Parent, J. 1996. Signalment and seizure pattern in the diagnosis and treatment
of recurrent seizures. ACVIM-Proceedings of the 14th Annual Vet. med. Forum. p.
Copyright © 1998
Canine Inherited Disorders Database. All rights reserved. Revised: October
This database is a
joint initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic
Veterinary College, University of Prince Edward Island, and the Canadian
Veterinary Medical Association.