A seizure generally has four stages including the proderm (hours before), aura (minutes before), ictal (during) and post-ictal (after). In the proderm, aura and post-ictal phases, behavioural changes may be noted. During the ictal phase, loss of consciousness and muscle convulsions may occur.

Seizures can be further classified as focal or generalised. During focal seizures, only a single side of the brain is affected, while in a generalised both sides are involved. Focal seizures usually present as involuntary limb or facial movements. Consciousness is not always affected. Generalised seizures are usually characterised by involuntary movements and loss of consciousness. Seizures can occur in small clusters or go on for a prolonged amount of time (grand mal or tonic-clonic seizures).

Testing is a process of elimination and may include blood tests, spinal fluid analysis and advanced imaging for the brain (CT or MRI). It is unclear if there is a gender predisposition, with some studies showing males are more likely to be affected and there is a known genetic basis in some breeds like keeshonds, German shepherds, border collie, labradors and golden retrievers.

In general, epilepsy is more difficult to control in large breed dogs and anticonvulsant therapy is the treatment of choice for idiopathic epilepsy. Multiple therapies may be needed and ongoing monitoring is required. Patients with epilepsy can live a long, happy life however, require ongoing management, medications and dedicated owners.