We have all experienced our dog lying peacefully by our feet when all of a sudden he or she starts twitching. The tail starts wagging. The legs and feet take on a running motion. Rover begins making noises. Sometimes the noises seem to indicate excitement over something. Sometimes the noises sound distressful.
Are these things indications of dreams?
There is not a lot of known research. However, experts do believe that dogs do dream. It is believed that dreaming is a necessity of life. Its purpose is to allow time for data processing and memory storage.
Dogs do think and they have memory. Just as people, they need a period where their memory banks are purged and reorganized.
Scientists believe that dogs sleep in the same manner as people sleep. The use of an electroencephalogram (EEG) allows researchers to measure the brain wave activity of dogs during their sleep cycle. This has shown that dogs first enter a lighter sleep mode where they breathe regularly and can be awakened easily before reaching a deeper stage of sleep where the breathing tends to become irregular and it is harder to awaken the dog.
Dogs, like humans, experience two main types of sleep – rapid eye movement, which is referred to as REM, and slow wave sleep, which is known as SWS.
The first stage of sleep is thought to be the SWS stage, also called the “sleep of the mind.” It is in this stage that the dog’s mental processes tend to be muted. However, muscle tone remains unchanged.
In SWS, the brain waves are slower, undulating and similar to a state of light anesthesia. The dog appears to be calm and resting peacefully during this stage. He or she can easily be aroused from the SWS sleep stage.
REM sleep follows that of SWS sleep. REM sleep is often referred to as the “sleep of the body.” During this stage of sleep, the dog’s body tends to be very relaxed. However, the mind appears to be racing and the dog’s eye movements will be rapid.
It is thought that dogs dream during the REM stage of sleep. The rapid eye movement may be an indication that the dog is watching whatever they are dreaming about. In REM, the brain waves are irregular and rapid. The dog will experience involuntary body movements, as wells as vocalizations. You may hear growling, barking, whining, whimpering or howling.
Dogs are the most relaxed during the REM stage of sleep. It can be hard to awaken a dog during this stage. When humans are awakened from the REM stage of sleep, they report dreaming. Thus, it is also thought that dogs are experiencing the same thing.
Adult dogs spend about 10 to 12 percent of their sleeping time in the REM stage. Puppies spend even more of their sleep time in the REM stage. It is thought that is because puppies need more time to compact the new data that they learn.
So the next time you see your dog running in his or her sleep, relax and sit back. It is a normal phenomena and it is best not to interrupt.