This chemical controls alertness and has a significant effect on sleep patterns. Narcolepsy is caused by lower than normal levels of a neuropeptide called orexin (or sometimes hypocretin) in the brain. It’s not known if dogs experience hallucinations as humans do. Dogs with narcolepsy also appear somewhat inactive during the day, but sleepiness is less common or less noticeable than in humans. The episode is usually brief, but if the stimulus continues, the dog may experience another attack. The dog usually passes through three stages with measurable changes in their brains: the first stage is characterized by paralyzed muscles but waking EEG in the brain and normal visual tracking in the second the brain reaches a sleeping state similar to REM, while in the third, normal EEG returns before the dog wakes up. Cataplectic attacks often occur in response to a stimulus that generates excitement, such as food or toys. In dogs, cataplexy is the defining symptom. The Canine Narcolepsy Colony at Stanford University focuses on breeding and studying dogs with narcolepsy. The percentage of dogs with the condition is not known it is more common in some breeds especially Doberman Pinschers and Labradors.

In humans, it affects about 0.05% of the population. Narcolepsy is a rare condition characterized by excessive sleepiness and brief attacks of cataplexy or muscle weakness.

Cataplexy video