THERE'S ARGUABLY NO MORE PEACEFUL SCENE...
...than a dog asleep in front of the fire. But then his breathing hikes and his legs twitch as if he's dreaming. But is that even a thing? Do dogs dream?
Sleep in dogs is a fascinating topic because the characteristics of canine sleep share much with humans. From rapid eye movement (REM) sleep with dreams of rabbits to the relaxation of non-dreaming, non-REM sleep, we know a surprising amount about dogs and what happens during their catnaps.
1: Let Sleeping Dogs Lie
It is no surprise to any dog owner to learn their fur-friend sleep more than they do. A dog spends a little over half (56%) of any 24 hours asleep, whilst for a person the average is eight hours. The breakdown of a dog's snooze time is approximately:
23% spent in the deepest sleep state, called slow-wave (non-REM) sleep
12% in a REM sleep or a dreaming state
2: Rover's REM and non-REM Sleep
In a similar way to people, dogs experience both rapid eye movement (REM) and non-REM patterns of sleep. It's no surprise dogs have non-REM sleep, as scientists believe all vertebrate animals share this in common. Indeed non-REM sleep is deep, non-dreaming rest where the body is totally relaxed, the breathing and heart rate slow, and the brain inactive.
What's more interesting is that dogs do experience REM phases of active dreaming, just like people. The purpose of REM is to allow the brain to process information gathered during the day. It is a time of dreaming when the brain explores random ways of connecting events to see what makes the most sense. Its importance is such that a lack of REM sleep is linked to poor memory and increased difficulty learning.
3: What Do Dogs Dream About?
When Rover's legs twitch and he woofs in his sleep, is he chasing rabbits?
Scientists believe the function of REM sleep is to process information, so it makes sense that dogs dream about doggie things such as barking at burglars and stealing biscuits. Signs of this include his legs twitching, and an increased heart and respiratory rate.
It's also likely that dogs suffer from nightmares, given that brain activity patterns are seen that are similar to those in people having bad dreams. Indeed, another similarity is that a strain of Weimaraner dogs has been identified as suffering from narcolepsy, a condition that occurs in people where the patient falls spontaneously and suddenly asleep, often at inappropriate times.
4: Puppies and Senior Dogs are Different
Anyone who has watched a puppy sleeping may notice how active he is when asleep, compared to an adult dog. This is because an area of the brain called the pons is responsible for inhibiting the movement of major muscle groups. This stops the dog (or person) acting out their dreams whilst resting.
However, in the very young the pons is less well-developed and less effective at shutting down this activity. So puppies (and also senior dogs) move around more than adult dogs and tend to twitch and vocalize in their sleep.
5: Size Matters
One bizarre fact about dog sleep is that sleeping patterns are influenced by the size of the dog. The average dog is asleep for around 20 minutes before he enters REM sleep, which then occurs in bursts of two to three minutes at a time.
However, this pattern is partially dependent on the dog's size. For example, large breeds tend to dream less often but for longer periods of time, and small breeds dream more frequently but in shorter bursts.
Next time your dog is dozing in front of the fire, leave him to his beauty sleep. That snooze helps him make sense of the day. Fingers crossed he has sweet dreams, but if he does seem agitated then he might be having a nightmare, so speak softly to comfort him.
Information, suggestions or opinions about canine nutrition or general canine health contained within this website are not intended to be, nor should they be interpreted as, veterinary medical advice and should not be used to contradict or replace the expertise and judgment of your veterinarian or any other veterinary professional.