Dogs have a sleep pattern similar to humans, but with some relevant differences that they have inherited from their wild ancestor, the wolf. In addition, they sleep many more hours a day than we do. In this post we explain the importance of canine rest, its main characteristics and we answer to the question of if dogs dream, if they can have nightmares, etc.
What is the dream for?
Rest is key for any species. Most animals have a biological rhythm of rest-activity that allows them to restore their energy.
The dream helps the dog to fix his experiences and what he has learned during the day, among other essential functions.
As the neurologist and neuroscientist Facundo Manes explains , sleep is important for the following reasons:
- It allows the animal organism to conserve and restore its energy.
- Agile keeps the brain .
- Improves learning .
- It helps to consolidate new memories and update old ones based on what the animal has just learned: the sleeping brain knows what new information is significant enough to maintain it and which is not worth it to be retained.
- Forge new neural connections.
- It allows the growth: during the sleep the hormone of the growth is released , for that reason to understand how the dogs sleep and the importance of the rest is fundamental when we speak of puppies.
- Prevents cerebral degeneration: during the sleep increases the activity in the genes involved in the production of “oligodendrocytes”, which are the cells responsible for coating the myelin neurons, the “insulating material” of the brain. On the contrary, the lack of sleep produces greater activity in the genes involved in stress and cell death.
- It improves the immune system .
A dog that does not rest properly can have learning and memory problems, as well as a weaker immune system that leaves him exposed to diseases.
Keys to understanding how dogs sleep
Although it seems contradictory, the dream is not a passive activity but extremely active. While a dog sleeps his brain is continuously working.
During sleep, postural relaxation occurs and sensory thresholds are raised so that the dog can disconnect from the environment, so to speak.
Dogs, like humans, are polyphasic sleepers, which means that they alternate different phases within the dream, one deeper than the other. Each of them has certain functions.
The brain of the dog works based on brain waves, depending on how these waves are, the dog will be in the waking or sleep phase.
Dogs, like people, alternate phases of short or slow wave sleep and fast wave or REM sleep. To understand how dogs sleep, it is essential to know what happens in each of these phases.
Within the dream we find two major stages or phases:
- Slow sleep, short wave or sleep No REM
- Dream REM (Rapid-Eyes-Movement)
Slow sleep or NREM
During the NREM sleep the brain of the dog is calm and his body, although relaxed, could move or change position. Decreases heart rate, lowers body temperature and releases growth hormones. During this phase of sleep the dog does not dream.
REM sleep (deep sleep)
During the REM phase, the dog sleeps deeply and dreams . The breathing is fast and irregular and the dog can shake, move its legs as if it were running and even articulate sounds and bark.
REM comes from the English phrase “Rapid Eyes Movement”because during this phase of the dream the eyeballs move rapidly under the eyelids. Sometimes this can be easily observed because the dog falls asleep with eyes slightly open.
The REM phase is the phase during which the dog dreams and captures a lot of information from the environment due to the high brain activity it has. In this phase, in fact, the level of brain activity is similar to when the dog is awake.
The dog has inherited the wolf’s dream
If we talk about how dogs sleep, it is inevitable to refer to their wild ancestors.
Dogs often wake up during their rest. In the same way that wolves do (which are their ancestors in the evolutionary chain), they alternate sleep with waking hours.
As veterinarian specialized in neurology Valentina Lorenzo explains: “Dogs spend more time in wakefulness than people during the night and wake up many more times. They sleep between five and twenty minutes in a row and another five minutes are revealed, after which they recover their sleep again. This behavior responds to the dog still retains many of the behaviors of his ancestor, the wolf .
Do not forget that dogs are predators (hunters) and need to be alert. For that reason, their REM phase of deep sleep lasts little and they can wake up quickly if a threat arises in the environment. Sleeping too deeply could be dangerous. Imagine feral dogs or wild dogs, which live in a competitive natural environment and it will be easy for us to understand.
Have you ever wondered why your dog seeks to sleep or rest near you?
The answer is that dogs are social sleepers. That is, they need to sleep while in contact with another dog or with their human companions. If it is not physically, at least yes in the same room. That allows them to feel more secure and relax better.
It is about the expression of a conservation instinct: if a dog is sleeping outdoors alone, it should be continuously alert to avoid threats or dangers present in the environment. We return again to the legacy of the wolf …😉
For that reason it is not advisable to force a newborn puppy home to sleep alone and isolated. And since we talk about this, I remind you that in this post we explain what to do if your puppy cries at night .
Active rest postures and deep sleep postures in dogs
We talk about how dogs sleep, but we also have to keep in mind how they rest, even without being asleep.
Dogs adopt a wide variety of postures when resting and sleeping. Some of them allow them to be at rest but alert, and others help them to fall asleep.
During the active rest, which is the one that allows your dog to spend the minimum energy while being alert of what happens around him, your dog can be sitting or lying on his sternum. If you adopt a lying position, you will never be on your side because what the dog is looking for during active rest is to be able to react quickly to any unforeseen event or threat.
Dogs only sleep soundly and dream when they are lying sideways, curled up or belly up. They are positions that do not favor a quick reaction to a threat and only adopt them when they are absolutely relaxed.
How many hours does a dog sleep?
The hours that a dog sleeps depend on the age, the physical condition and the rhythm of daily activity carried by the animal and its owners.
In general, and as the clinical ethologist veterinarian Rosana Álvarez explains , an adult dog that lives in a family environment will sleep during the middle of the day.
How much does a dog sleep? An adult dog usually spends 44-48% of its waking time, 19-21% in sleepiness, 22-23% in slow wave sleep and 10-12% in REM sleep. That is, 50% wakefulness and 50% sleep, be it more or less deep.
If we take as a measure a whole day, 24 hours the dog spends an average of 9.67 hours in slow wave sleep and about 3.24 hours in deep sleep.
It must also be borne in mind that sleep patterns in an adult dog will vary according to the photoperiod, the daily activity of the dog and familiarity with the environment: a dog in a new or unknown environment is always more alert, so it can happen.
How much does a puppy sleep?
Puppies need more sleep than adult dogs.
In the two weeks following birth, the puppies only show patterns of deep sleep. In this neonatal period, the type of sleep that is observed is of the REM type.
During the third week, or transition period, they begin to alternate slow wave patterns and REM. The time the puppies spend awake increases as the time of deep sleep decreases. At this time it is not so common to go directly from being awake to deep sleep.
A puppy dog sleeps much more than an adult because it needs to fix much more information of the environment (everything is new and everything is yet to learn) and, in addition, it needs to grow and the growth hormone is segregated during sleep. A puppy of less than three months can get to sleep between 18h and 20h daily.
After 4 weeks of life , the puppies begin to interact much more with the environment and therefore remain alert more than 50% of the time. Little by little, and until 8 weeks , when the stage of socialization begins , sleep patterns are increasingly similar to those of the adult dog.
Do dogs dream?
We have seen how dogs sleep but we still have to answer the question of whether they can dream.
Given the similarities between the sleep patterns of dogs and humans, it would be strange to think that dogs can not dream. However, we still have not been able to demonstrate what they dream of, although logic leads us to think that they recover experiences lived in their day to day and, therefore, they dream of “dog things”.
Thanks to the study of encephalograms that analyze brain activity, scientists have shown that dogs dream and do so during the REM sleep phase.
Do dogs have nightmares?
Just as we can say that dogs dream, we could deduce that dogs also have nightmares . In fact, at times we can watch our dog shake during the REM phase as if it were very alternate and even vocalize (bark and growl). Although today there is no scientific way to verify what images or stimuli are evoking the brain of the dog during this phase of sleep, everything indicates that dogs can have, just like people, unpleasant or unpleasant dreams and sudden awakenings because of of these nightmares.