Also referred to as Junevile Myoclonic Epilepsy (JME).

Affected dogs displayed frequent myoclonic jerks or twitches, which start to occur around 6 months of age.

Owners of the affected dogs described the myoclonic jerks as severe startling or even resembling an electric shock.

The myoclonic seizures can be triggered by visual stimuli, such as light flashes, a sudden incidence of light or flashing light on the sea waves.

Photosensitivity was recognized in 35% of dogs.

The twiches mostly occur when the dog is in the relaxed state, drowsy or when falling asleep or napping.

Twitches can occur also during sitting, standing or walking.

There were no noticed changes in the behavior.

The myoclonic jerks were mostly limited to the trunk, proximal limb musculature, cervical musculature producing nodding movements of the head, and the face.

The intensity can vary between events and affected dogs.

After the seizure, the dogs seem confused and scared.

Due to the seizures, sleep among those dogs was impaired.

The frequency of the twitches can go up to 150 twitches per day.