Canine idiopathic epilepsy: prevalence, risk factors and outcome associated with cluster seizures and status epilepticus

Abstract

Objectives: To evaluate the prevalence of cluster seizures and status epilepticus in dogs with idiopathic epilepsy and determine risk factors for cluster seizure frequency, severity and patient outcome.

Methods: Retrospective review of medical records of 407 dogs with idiopathic epilepsy was made. Follow-up questionnaires were evaluated in cases with cluster seizures.

Results: Mean age at diagnosis of idiopathic epilepsy was 4 years. Cluster seizures were documented in 169 (41%) dogs. German shepherds and boxers were significantly (P=0·04 and 0·01, respectively) more likely to suffer from cluster seizures compared to Labrador retrievers. There was no association between the occurrence of status epilepticus and cluster seizures and frequency and severity of cluster seizures and status epilepticus episodes with age or breed. Intact males were twice as likely (P=0·003) than neutered dogs to suffer from cluster seizures. Intact females had significantly (P=0·007) more frequent cluster seizures than neutered dogs. The median survival time for all dogs with cluster seizures was 95 months. Significantly (P=0·03) more dogs with frequent cluster seizures were euthanased because of the cluster seizures.

Clinical significance: There was a high prevalence of cluster seizures in dogs with idiopathic epilepsy. Neutering status appears to influence cluster seizure occurrence with intact females more likely to experience more frequent episodes. Euthanasia is associated with frequency of cluster seizure episodes.