Dog Dreams

Your dog lies asleep at your feet, and suddenly his legs begin to twitch and run. Is he dreaming?

Although no one really knows the true function of dreaming it does seem to be necessary for normal data processing and memory storage. Dogs think and they have memory. And their memory banks need period purging and reorganization during sleep just as ours do.

Dogs and humans are not as different as some scientists would have us believe. Scientists tend to dwell on the differences between the two species, whereas the sameness is positively compelling. We are 95 percent identical genetically and physically (right down to the iron-containing porphyrin ring our common blood pigment, hemoglobin).

Because of this blue print similarity, you might expect a lot of the inner workings to be the same –and they are. Our brains are similar, our neurochemistry is the same, and our reflexes and memory are "wired" in like manner.

Types of Sleep

Like humans, dogs have two main types of sleep: rapid eye movement (REM) sleep and slow wave sleep (SWS). As a dog falls asleep the first stage he enters is SWS, the "sleep of the mind," in which mental processes are muted but muscle tone remains. The next stage is REM sleep, the "sleep of the body," in which the body is fully relaxed but the mind is racing and the dog's eyes are darting rapidly.

In SWS, brain waves are slow, undulating and of high amplitude much like those in a lightly anesthetized animal or person. In this stage, the dog appears calm and at rest. Dogs and humans are more easily aroused from SWS sleep, which appears to be a transitional state with incomplete muscle relaxation.

By contrast, in REM sleep brain waves are rapid and irregular, like those of the awake state. Dogs, like people, display REM sleep, and during REM sleep they show evidence of heightened mental activity – fast electroencephalogram [EEG] (brain wave) pattern. They may move their legs as if they are running, may whine or whimper as if excited, and may breath rapidly or hold their breath for short periods.

When REM sleep is achieved they are at their most relaxed and are most difficult to waken. It is during this more profound physical sleep that their eyes begin to dart and the brain waves pick up pace. Humans awakened from this state report that they have been dreaming; dogs are probably dreaming too when they are in REM sleep, although no dog has ever told anyone about a dream he has had.

Incidentally, adult dogs spend about 10 to 12 percent of their sleeping time in REM sleep. Puppies spend a much greater proportion of their sleep time in REM sleep, no doubt compacting huge quantities of newly acquired data.

And if you have ever wondered whether dogs that seem to be running during sleep are dreaming of catching rabbits or something similar, you can safely say they are.

Sleep Behavior of Dogs

There's no doubt about it: dogs sure know how to sleep. The amount of time spent napping varies from dog to dog and depends on the dog's age and personality. Counting little naps and longer snoozes, most dogs sleep about fourteen hours a day.

Nobody is sure why dogs sleep so much. The amount of sleep that an animal needs depends upon its species. Horses and cows may sleep only three or four hours daily, because they require long hours of grazing to supply their bodies with sufficient food. Bats and opossums may sleep closer to 20 hours.

The various breeds of dogs also seem to have different sleep requirements. Some very large breeds of dogs, like Newfoundlands, Saint Bernards, and mastiffs, often spend a great deal of their lives sleeping – perhaps up to sixteen or even eighteen hours a day.

For this reason they were often referred to as "mat dogs," because they could always be found lying in front of the fireplace, much like a giant, furry hearth mat.

Dogs sleep more than us, but they wake more frequently than we do. How much and when they sleep depends on the level of activity in their environment. A dog living as a pet in the home is likely to sleep more than a dog that works for a living, like a search and rescue dog or a dog working on a farm. Dogs are lucky – they are able to adjust their sleep pattern so that they can be awake when there is something to do, and asleep the rest of the time.

Of course, today's modern indoor dog sometimes sleeps out of boredom. You can help your pet by providing plenty of stimulation during the day – this can be in the form of toys, a companion, or plenty of walks and playtime with you. If he has enough to do during the day, he may stay awake when the sun is up and sleep at night when you do.

Sleep Patterns

Dogs have the same sleep patterns as humans. When your dog first goes to sleep, he enters the slow wave or quiet phase of sleep. He lies still and is oblivious to his surroundings. His breathing slows, his blood pressure and body temperature drop, and his heart rate decreases.

After about ten minutes, your dog enters the rapid eye movement (REM) or active stage of sleep. He rolls his eyes under his closed lids, he may bark or whine, or may jerk his legs. During this stage, the brain activity is similar to that seen during the dreaming sleep of humans, and is evidence that dogs have dreams.

Incidentally, adult dogs spend about 10 to 12 percent of their sleeping time in REM sleep. Puppies spend a much greater proportion of their sleep time in this type of sleep, no doubt compacting huge quantities of newly acquired data.

Where Dogs Sleep

You may think your dog will sleep anywhere, but some dogs are very particular about where they sleep. In the wild, dogs sleep in dens, and your dog may seek out a sheltered place in your home, such as under a bed or in a closet. You may notice your dog circling or pawing at his sleeping place before he settles. This is to make a comfortable, den-like depression in which to sleep (even though it doesn't have much impact on a short pile rug).

You can make a comfortable bed for your dog or choose from the variety of plush beds at your pet store. Some people love snuggling up to their dogs at night and there is no question dogs love sharing their owners' bed. Advocates of this method say it strengthens the human-canine bond – not to mention the comfort and warmth your dog can provide for you. However, some animal behaviorists say this can upset the sometimes precarious hierarchy, because the dog may get delusions of grandeur. In other words, he may think he is higher on your household's social scale than some other members of the family. Four-on-the-floor may be the order of the day for some of these characters.