“Narcolepsy” refers to sudden daytime sleepiness, lethargy or brief periods of collapse, paralysis and unconsciousness that resolve spontaneously (called “cataplexy”). It is a specific medical condition that involves much more than mere tiredness, and the disorder is still not well understood. Narcolepsy affects humans, cats, dogs, cattle and horses and is probably largely genetic. It is not normally life-threatening and is not painful. It is rare in companion cats.
How Narcolepsy Affects Cats
Cats suffering from narcolepsy fall into a deep sleep (or become unconscious) abruptly, become partially or completely paralyzed and then awaken with complete recovery, as if nothing had happened. Narcolepsy is not simple sleepiness or cat-napping and is neither life-threatening nor painful. Affected animals frequently exhibit muscle twitching as happens during periods of deep, rapid eye movement (“REM”) sleep. Narcolepsy is more common in young animals. It usually occurs during the daytime and often is precipitated by activity, eating or excitement. The episodes tend to be short - seconds to minutes - and can recur frequently or only occasionally. Most affected cats can be roused by loud noises, petting or other external stimuli. Narcoleptic episodes can be mistaken for epileptic seizures. Again, this disorder is rare in domestic cats.
Symptoms of Narcolepsy in Cats
Narcolepsy is thought to be an inherited condition that has been reported but is rare in domestic cats. Clinical signs usually develop between 4 and 24 weeks of age. The main sign of feline narcolepsy is suddenly falling into what appears to be a deep sleep during the daytime. The onset usually is rapid, and the episodes typically last from a few seconds to a few minutes, although they can last much longer. Signs are characterized by collapse into lateral (lying on the side) or sternal (lying on the stomach) recumbency. Owners may notice twitching of the muscles around the eyes and elsewhere. Narcoleptic episodes often occur during times of regular activity, such as eating, playing or other times of excitement. For example, a cat playing with a toy might suddenly fall to the ground in an apparent “deep sleep,” and then spontaneously awaken and begin playing again as if nothing unusual had happened.
Narcolepsy is also characterized by a condition called “cataplexy,” which involves brief episodes of muscle paralysis with complete loss of reflexes that spontaneously return. The cat may develop weakness in its legs, its facial muscles may slacken and droop and its neck muscles may tremble, with its head “falling down.” After a short period of time, the cat typically will act normally. Most affected cats can be aroused by loud noises, petting, calling or other external stimuli.
The frequency of narcoleptic symptoms depends upon the severity of the condition. Some cats experience only a few narcoleptic bouts each week or month, while others may experience dozens of narcoleptic episodes daily. Signs of narcolepsy can mimic signs of other more serious conditions such as heart disease, diabetes or epilepsy. If you notice any of these signs in your cat, make an appointment with your veterinarian as soon as possible. Narcolepsy normally can be managed, and there are measures that cat owners can take to keep their narcoleptic friends comfortable and safe.
How often the symptoms of narcolepsy occur depends on the severity of the condition. Some cats experience a few narcoleptic bouts a week, and others may experience dozens of narcoleptic bouts a day. Symptoms of narcolepsy are also similar to symptoms of other serious conditions such as heart disease, diabetes, or epilepsy. If you notice any of these symptoms occurring in your cat, make an appointment with your veterinarian as soon as possible. Narcolepsy can sometimes be treated, and there are measures that a pet owner can take to keep their narcoleptic friend safe.
Treating Feline Narcolepsy
While there is no cure for narcolepsy, the clinical signs normally can be minimized with medical treatment. Sometimes, the signs resolve without medical attention. Treatment is generally only necessary if the cat is experiencing frequent or severe cataplectic episodes that interfere with its quality of life. Thankfully, this is uncommon. Narcoleptic cats that cannot be regularly supervised (especially if they are allowed to roam freely outdoors) should be placed on management therapies. While the episodes themselves do not hurt the cat’s health, they can occur at inopportune times, such as in the middle of a street or while climbing a tree, potentially causing serious injury to the animal.
The current medical treatment protocol for animals with narcolepsy is administration of tricyclic antidepressants, which block cellular uptake of the neurotransmitter, norepinephrine. Stimulants are available to treat excessive sleepiness, as well. Of course, new medications are constantly being researched and developed. All medications can have unwanted side effects. If you and your veterinarian decide to place your narcoleptic cat on medication, make sure that you are fully informed about all possible risks and side effects so that you can make an informed decision regarding the treatment protocol.
It can be very upsetting for owners to see their cat collapse or go through a cataplectic episode. However, owners should be reassured that narcolepsy is not a life-threatening disorder, and that with management their cat should not suffer adverse effects from this condition.
Diagnosis of feline narcolepsy is best done at a veterinary teaching hospital or other highly specialized medical facility, as most general veterinarians will not see it during the course of their practice.