The other day my cat, Buddy, was sleeping soundly when suddenly he let out a piercing cry. Going to see what had happened, I was surprised to see that he was still sound asleep, his feet were twitching, but he was out. I knew that animals had dreams, but Buddy was talking in his sleep! He was clearly dreaming about something that was distressing to him, perhaps the cat from next door? Or maybe he was reliving something from his life before I adopted him. There is no way to know. But we do know that animals are capable of having complex dreams, just as we do.
Studies have proven that other mammals show the same level of brain activity and increased heart rate during REM sleep (the cycle of sleep where dreaming occurs) as humans. Although no one really knows the true function of dreaming, it does seem to be necessary for normal data processing and memory storage in humans. So, it seems likely that the same is true for animals.
Dogs and cats are champion sleepers, clocking a lot more hours of shut-eye than we do. Most dogs sleep 12 to 14 hours a day, and cats sleep 13 to 18 hours. Much of their sleep time is really napping as they wake more often than we do.
During their dreams, it is normal for animals’ paws to flex and relax, whiskers to twitch, and legs to move, even making a full running motion. Apparently, Buddy’s slumbering vocalization is not that unusual; dogs are known to bark during their sleep and cats to chatter.
People have two main types of sleep: slow wave sleep (SWS) and rapid eye movement (REM) sleep. As we fall asleep, the first stage we enter is SWS, mental processes slow but muscle tone remains. The next stage is REM sleep; the body is relaxed but the mind is active and the eyes may be darting rapidly. Our pets go through these same sleep stages.
Studies conducted in 2000 at the Massachusetts Institute of Technology indicate that not only do animals dream, but their dreams can be highly complex involving long sequences of replayed waking events. Prior to these studies, many scientists believed that only a few species of animals, such as dolphins and primates, were capable of recalling complicated memories.
The MIT research convinced many scientists that most animals not only dream, but are capable of intricate thought processes, able to retain and recall long sequences of events, and are capable of re-evaluating their experiences.
In his best selling book, The Cat Who Came for Christmas, Clevaland Amory describes the rescue of his white cat, Polar Bear, from the streets of New York. He explains that after his rescue, Polar Bear spent a great deal of time sleeping. “During his sleep he was obviously dreaming. . . He would twitch, often gently but at other times violently, both front and back paws moving – sometimes so violently that he woke himself. At such times he would be alert very quickly, casting a look around and a casing of all fronts. . . Finally, after satisfying himself that the present, not the past, was the reality, he would blow out a little sigh, and immediately go back to sleep.”
Amory goes on to say, “I believe [animals] dream exactly the way we dream, and about everything in their lives – that they have good and bad dreams in almost direct proportion, as we do, to whether their lives have been more good than bad. Unfortunately, because the majority of animals have it so much tougher than we do, I believe that the majority of dreams, except in the most fortunate petdom, are bad.”
Sadly, Amory is probably right about this. But from a different perspective, realizing that animals also dream and that the nature of their dreams is so very similar to our own, adds to our understanding of animals and gives me a deeper appreciation of the many things we share in common.