Narcolepsy is a condition characterized by an extreme tendency to fall asleep whenever in relaxing surroundings.
Cataplexy is a medical condition in which strong emotion causes a person or animal to suffer sudden physical collapse though remaining conscious.
The two conditions are disorders of the nervous system. Narcolepsy is excessive daytime sleepiness, lethargy, or brief periods of collapse and unconsciousness that resolve spontaneously. Cataplexy is characterized by brief episodes of muscle paralysis with loss of tendon reflexes; the animal stays alert and will follow with his eyes. These brief episodes of motor inhibition are completely and spontaneously reversible.
These central nervous system disorders usually occur together in most dogs although narcolepsy can occur without cataplexy. The episodes may last from few seconds to more than 20 minutes. A dog can suffer from several episodes of necrolepsy and/or cataplexy a week to more than hundred a day. In between the episodes, the dog is normal.
These disorders are not related to any underlying condition. Dogs suffering from these episodes, do not necessarily have any other primary of secondary physical or neurological disorder. These episodes often occur when the dog is eating, playing, excited, or is engaged in sexual activity. Moments of heightened emotion play a role in both conditions and in the onset of an episode.
During a narcopletic episode, the dog suddenly collapse onto its side or stomach, with slacken muscle and all physical movements briefly ceased. The dog appears to be in a state of deep sleep, also known as rapid eye movements or REM.
On the other hand, during a cataplectic episode, the dog becomes paralysed although it can control its eye movements and remains aware of what is happening around it. It is just that it looses control over its body movement and the body becomes paralysed.
The dog comes out of both conditions in response to an external stimuli such as when it hears loud sounds, or when it is petted.
Some of the usual symptoms of narcolepsy and cataplexy are:
Rapid onset of episodes, with no apparent warning of imminent collapse
Sudden loss of consciousness
Paralysis of limbs, head, and torso
Episodes last from several seconds up to 30 minutes
Eye movement, muscular twitching, and whimpering during episodes
Episodes usually end when stimulated by petting, loud noises, etc.
