Sleep is a favorite pastime of many pets. Cats especially are known for their love of slumber; so much so that they even have a nap named after them. But when a pet falls asleep suddenly then wakes abruptly or seems unusually lethargic during the day, it may be time to look at narcolepsy. While narcolepsy is not painful or especially dangerous for a pet, it is important to reach a correct diagnosis with your veterinarian as the symptoms of narcolepsy can mimic those of more serious health conditions, such as heart disease, epilepsy, and diabetes.
What Causes Narcolepsy in Dogs and Cats?
The causes of narcolepsy in dogs and cats are not well understood, but it is thought to be an inherited condition. Researchers have identified an inherited form of the disease in a family of Doberman Pinschers, and the responsible gene involves a defect in a chemical neurotransmitter called hypocretin. Hypocretin is involved in regulating normal sleep cycles, and abnormalities have been found in hypocretin receptors in dogs, mice, and people with narcolepsy. There does not seem to be any such connection in cats, but the condition is still thought to have a genetic component in most cases.
Outside of Doberman Pinschers, other predisposed dog breeds include the Labrador Retriever, the Poodle, and the Dachshund.
Symptoms of Narcolepsy in Dogs and Cats
In both dogs and cats, the primary symptom of narcolepsy is suddenly falling into a very deep sleep. The sleep comes on abruptly, and often at strange times -- like when a pet is eating or playing -- then resolves spontaneously in a matter of seconds or minutes. The pet will then go about their normal activity as if nothing happened.
Associated symptoms include:
- Sudden collapse onto the side or stomach
- Excessive daytime sleepiness
- Abrupt loss of conscious then sudden return to consciousness
- Twitching muscles (especially around the eyes)
- Rapid eye movements
- Cataplexy, a condition characterized by brief episodes of muscle paralysis and lack of reflexes. The episodes usually appear and resolve suddenly.
The frequency and severity of narcoleptic episodes will vary from pet to pet. Some pets have a few episodes per week while others have several per day.
In cats, symptoms usually appear between 4 and 24 months of age. In dogs, symptoms usually appear by the age of 6 months.
Diagnosing Narcolepsy in Dogs and Cats
Contact your veterinarian if your pet exhibits any of the above symptoms. While narcoleptic episodes themselves are not dangerous, they can be if your pet has an episode at an inopportune time, for example while swimming or perched on a tall surface. In addition, because narcolepsy symptoms can mimic those of other more serious health conditions, it is important to find out exactly what is going on in your pet.
Your veterinarian will examine your dog or cat, ask you questions about their symptoms, and perform a series of tests to rule out other medical conditions and reach a definitive diagnosis. For example, if you tell your veterinarian that your pet has episodes while playing fetch, your veterinarian may try to recreate that activity so that an episode can be observed.
A food-elicited cataplexy test may also be performed, as many pets suffer cataplectic attacks while eating. The test involves lining up pieces of food and timing how long it takes a pet to eat them as well as the time and severity of any narcoleptic or cataplectic episodes.
Treating Narcolepsy in Dogs and Cats
There is no cure for narcolepsy, and depending on the severity of your pet’s condition, your veterinarian may decide to hold off on treatment to see if the condition resolves on its own (it often does).
However if a pet is experiencing frequent or severe episodes that are interfering with their quality of life, your veterinarian may recommend treatment with tricyclic antidepressants. In some cases, stimulants may also be prescribed to combat excess sleepiness.
Even if medications do not fully eliminate episodes, you can rest assured knowing that your pet is not suffering. However, you should still keep an eye on your pet to ensure that they aren’t having episodes while in vulnerable positions or situations.
VetInfo - Dog Narcolepsy
PetWave - Dog Narcolepsy
PetWave - Cat Narcolepsy
PetMD - Narcolepsy and Cataplexy in Cats
Narcolepsy and Cataplexy in Dogs