Eagle Fern Veterinary Hospital

585 NW Zobrist Street
Estacada, OR 97023



 Eagle Fern Veterinary Hospital Logo  Seizures                                         


Epilepsy is the most common neurological problem in the dog. Epileptic seizures are a sign of a sick brain. The outcome of the illness may vary from one that requires no treatment, treatment with one or multiple drugs or may be unmanageable and result in death. If possible, the underlying cause of the seizure should be identified. Blood tests including a complete blood count and chemistry analysis should be performed on all animals suspected of having a seizure disorder, even if only one seizure has been seen.


The earlier anticonvulsant therapy is started, the better the potential outcome may be for seizure control. Therapy should be started if the dog has a seizure lasting longer than 30 minutes, cluster seizures or 2 or more seizures in a 3 month period. Some neurologists recommend starting therapy if any seizures are noted to minimize brain damage. Also, all of the seizures a dog may have had may not have been observed by the owner.  A log should be maintained to document observed seizures in order to help decide when to start therapy or determine benefit of therapy the dog is on.


Treatment is usually started out with the drug, Phenobarbital. It is relatively inexpensive, well-tolerated and can be administered two to three times per day. Potassium bromide may be added if Phenobarbital alone is not working. Potential adverse effects of both drugs are sedation and/or a less active lifestyle, anxiety or agitation, and increased thirst, appetite and urination .


Once started on therapy, serum levels of the anticonvulsant drug is measured at 14, 45, 90, 180, and 360 days then at 6 month intervals thereafter, if at any point a dog has more than two seizure events between these scheduled times, or 2 weeks after a dosage change. This is necessary to determine if a therapeutic level is present and to prevent toxicity. Blood samples are best taken in the early morning, prior to dosing, in a fasted dog. Annual complete blood count and chemistry analysis should also be performed to uncover any hidden adverse reactions to the medication.


Adjustments to the dosage of anticonvulsant drugs should only be made on the basis of blood level testing. The owner should contact the office before any adjustments are made in the dosage or frequency of giving the drug. 


Owners should record seizure events, adverse effects, and changes in drug dosing on the log supplied on the back of this form.


Emergency therapy may still be required even if the dog is on medication. Call the office at any time if:

  1. A single generalized seizure persists for greater than 5 minutes.
  2. Status epilepticus (continuous seizure activity lasts longer than 30 minutes or repeated seizures with impaired consciousness) occurs.
  3. A dog has more than one seizure per hour for 3 consecutive hours, regardless of seizure length.
  4. A dog has more than three seizures per day, regardless of seizure length.


If a dog has cluster seizures often, a quick acting anticonvulsant may be sent home that can be administered rectally to stop the seizures. If seizures are not being controlled, a referral to a neurologist may be needed for more advanced diagnostics or anticonvulsant therapy.


Dogs that are seizure free for 1 year or longer are candidates for Phenobarbital withdrawal. Phenobarbital withdrawal must be gradual and monitored by drug levels or a withdrawal reaction may occur. 



Seizure Event

Adverse Event

Change in Drug Dose