Why Do Dogs Cry in Their Sleep?
If you have a dog, you've probably noticed that he occasionally cries during his sleep and occasionally twitches. Is he dreaming? And when dogs dream, what do they dream about?
Dogs can cry in their sleep because, like humans, they dream in their sleep. The sleep cycles of humans and dogs are very similar, so we know that dogs also have a REM sleep phase, and they dream in it.
To find out exactly how this all works, we'll have to look at the science behind sleep in dogs.
Sleep cycles in dogs
While we can't look inside our dog's head to see if he's dreaming, or what he's dreaming about, we can look into a dog's sleeping process for some insight.
All dogs need to sleep. Most dogs sleep at least 18-20 hours a day, and puppies sleep even more than that!
Whenever a dog sleeps, his consciousness and voluntary muscle activity are reduced. Because brain activity is reduced when your dog sleeps, the brain and body can recover from all the activities during the day.
A lack of sleep can cause physical problems in both animals and humans. When we look at studies of people who have been sleep deprived, we can conclude that sleep is absolutely crucial for the health of humans, but also for our dogs.
Part of the way our human brains process information is through dreams. We are able to look at the function of brains in people who sleep and associate a variety of brain wave patterns with different sleep cycles and dreams.
Studies have shown that dog brains respond to sleep in much the same way as our human brains.
The first part of a sleep cycle in dogs or humans is the non REM sleep phase. During this phase, the body slowly becomes more and more relaxed. The non REM sleep phase consists of four phases, with your dog sleeping the deepest in the last two phases.
After the non REM sleep phase comes the REM sleep phase. This sleep stage is associated with rapid eye movements, which is where the REM name comes from. REM stands for Rapid Eye Movement.
Brain waves in REM sleep are irregular and fast, and the brain is much more active than in non-REM sleep. During this heightened mental activity, we dream. During REM sleep, the dog will breathe faster, may whimper or bark softly, and twitch with its paws or mouth.
Comparisons of the brain waves during REM sleep and dreaming in dogs and humans lead us to conclude that dogs experience dreams just as humans experience dreams.
Dreaming is part of the normal sleep cycle, whether you remember your dreams or not. Dreaming is thought to allow your brain to process much of the information it has collected while you are awake, which is one of the reasons why sleep is critical to mental performance.
What do dog dreams look like?
We can't look inside our dog's brain like a movie, but scientists have been able to make certain assumptions about how dogs dream, based on the information they've been able to gather.
After about 20 minutes during the REM sleep phase, the average dog begins to dream. Behind their eyelids, their eyes dart around. Breathing often changes, becoming faster and heavier or shallow and irregular. Other muscles may start to twitch. Some dogs gently wag their tails, twitch their noses and mouths, wiggle their ears, and twitch their paws as if they were running. Vocalizations can also occur, from soft whines to loud howls.
The reason dogs and humans lie down and sleep during a dream is because of a structure in the brain called the pons. The pons is responsible for turning off physical movements during REM sleep.
Although we all know people who sleep, walk, talk or move in their sleep, the pons is still at work in these people to limit the amount of action a person (or dog) experiences while dreaming.
This helps to keep everyone safe. If your dog dreams of chasing a ball, it could be dangerous for him to run without realizing it. The punch cannot limit all movements, so your dog can move his paws in his sleep.
How many do dogs dream?
How long dreams last and how often they occur depends on the age, size and individual characteristics of each dog. In general, the younger a dog, the more likely it is to experience dreams.
Puppies form an incredible amount of new synapses in their brains and have a lot more new information to process than adult dogs, which is probably why their brains work harder while they sleep.
Some studies have also shown that the length and frequency of dreams differ in large and small dogs. Psychologist Stanley Coren noted that a small dog probably dreams every 10 minutes in short one-minute dreams, while a larger dog often dreams only once every hour to an hour and a half, but for up to five to 10 minutes at a time.
Is my dog crying because of a nightmare?
There isn't much evidence to suggest that dogs have nightmares, especially in the way humans experience them. Instead of remembering how scary a dream can have been, dogs seem to wake up from dreams where they howl and run, only to move and go back to sleep.
It can be tempting to wake up a dog that seems to be having a bad dream, but dreaming is normal. Your dog won't suffer from nightmares and sleep disturbances like you might experience yourself, so it's okay to let him sleep.
Author: Tom Marr viahondenblog.nl
Illustrations: Antonia Oana
This BLOG has been posted on our website as a guest blog with the author's approval.