If you've ever watched your pet twitch, twist, and growl when sleeping, you've probably wondered if he or she is having a particularly interesting dream that involves chasing mice or rooting through your trash can. For years, people have wondered if their furry friends experience the same vivid dreams that humans do. We've taken a look at the latest information and research on pet dreams in an attempt to answer the question.
What Happens During Sleep?
Whether you're a pet or a person, you pass through similar stages of sleep. When you first drift off to sleep, you enter the non-rapid eye movement (REM) phase of sleep. The Non-REM cycle involves three stages of increasingly deeper sleep. During the first stage, your body becomes very relaxed, and your brain becomes less active. The second non-REM stage is marked by a slower rate of breathing and a lower heart rate. Relaxation intensifies and brain activity slows further as you prepare to transition to the deep sleep that occurs during the third non-REM phase. Dreams do occur during this stage but usually aren't remembered.
After you've been sleeping for about 1 1/2 hours, you'll enter the rapid eye movement phase. As you've probably guessed, your eyes begin moving back and forth during this phase. If you watch a family member sleep, you may actually be able to see their eyes moving beneath their eyelids during this phase.
Brain activity, breathing and heart rate increase during this shallower phase of sleep. REM dreams are often vivid and surreal and easily remembered when you wake up. Fortunately, your limbs and muscles are temporarily paralyzed during this phase of sleep to prevent you from harming yourself during a particularly disturbing dream. You'll cycle between non-REM and REM sleep several times during the night, with each REM cycle lasting between 10 minutes and one hour.
What Does the Research Reveal?
Because the non-REM/REM sleep cycle occurs in all mammals, researchers believe that pets also dream. Unfortunately, your furry friends are never going to wake up and say, "You won't believe the dream I just had!". Although your pets can't share their dreams, Koko, a gorilla who has been taught sign language, has the ability to discuss what she sees while she's asleep.
In a People magazine article, researcher Penny Patterson mentioned that Koko has shared information about events that haven't actually taken place or people she hasn't met after she wakes up in the morning. If Koko can dream, it's perfectly reasonable to assume that your dog, cat or rabbit also has nightly dreams.
French sleep researcher Michel Jouvet decided to find out if cats dream during a 1959 experiment that involved destroying the part of the feline brain that stops them from moving during REM sleep. When the cats entered REM sleep, Jouvet reported that they jumped, pounced and stalked invisible prey.
A 2001 study by Massachusetts Institute of Technology researcher Matthew Wilson explored the issue by comparing the brain activity of rats while they were awake and asleep. Rats in the study often exhibited the same brain patterns during REM sleep as they did while running a maze while awake. The results lead Wilson to conclude that the rats were dreaming of running through the maze during the REM cycle.
Size matters when it comes to dreaming. Small animals, like rats, have very short REM cycles. Dogs and cats have longer cycles, but cycle length may still depend on the size of your pet. For example, a Rottweiler may experience longer REM stages than a Chihuahua.
Should I Wake My Sleeping Pet?
If your pet seems to be distressed by a dream, your natural reaction may be to wake and comfort him or her. Unfortunately, it takes a little while for a sleeping pet or person to transition from a dream to a fully awake state. Until that happens, your pet may think you're part of the bad dream and bite or scratch you. Unless your pet is in danger of harming himself or herself during a dream, it's best to let sleeping dogs (or cats) lie.
Do you have a question about your pet's health or need to schedule a checkup? Give us a call and let us know how we can help you keep your furry friend happy and healthy.
People: What Is Your Cat or Dog Dreaming About? A Harvard Expert Has Some Answers, 10/13/16
LiveScience: What Do Dogs Dream About, 2/17/16
AKC: Do Dogs Dream, 11/09/15
National Institute of Neurological Disorders and Stroke: Brain Basics: Understanding Sleep
MIT News: Animals Have Complex Dreams, MIT Researcher Proves, 1/24/01