Canine idiopathic epilepsy has an estimated prevalence of 0.62 per cent in primary veterinary practice (Kearsley-Fleet and others 2013) and as such is one of the most common chronic neurological diseases. Descriptions of ‘epilepsy of unknown origin . . . where no symptom characteristic of any other condition has as yet presented’ can be found in early veterinary textbooks (Kirk 1922) and although our knowledge is now considerably greater, and we are no longer treating it with arsenic, we are still a long way from preventing or curing this enigmatic disease. This article describes the diagnosis, management and considerations to take when dealing with this condition.