The records of 54 labrador retrievers with idiopathic epilepsy were reviewed. Exogenous factors played a minor role in the transmission of the epilepsy. Prodromal phase and aura were present in the majority of the dogs with generalised seizures. The ictal phase was characterised by long-lasting automatisms. Approximately half of the dogs had seizures more than once a month; the remainder ranged from one every two months to one every 12 months. The average frequency in dogs with generalised seizures (n = 49) was one every 65 days and in dogs with partial seizures (n 5) one every 205 days. Long-term follow-up was performed in 46 dogs, 37 of which followed a strict treatment protocol. Possible causes for the large variations in treatment results were analysed. One goal was identify objective aspects enabling a realistic prognosis prior to treatment. Animals with a high age at onset of seizure (mean, four years) showed an excellent outcome, even if treatment began late. Dogs with low frequency rates and low total numbers of seizures responded well to therapy if treated as early as possible.