Why does my dog wag his tail when he sleeps? Let’s Explore

Dogs Wag Their Tail During the REM Sleep Cycle

During the REM sleep cycle, dogs may wag their tails. Generally, this is the only time they do this because your dog is fully relaxed. Like people, dogs go through the REM sleep cycle or Rapid Eye Movement.

What happens during the REM sleep cycle? The REM sleep cycle is when a dog is in its deepest state of sleep. This is when it can dream and get the most restful sleep it can get. When a dog is in its REM sleep cycle, it can start wagging its tail for a few reasons.

Dogs “Sleep Wag” When They Are Happy

When a dog is having a good dream, it is probably happy. Naturally, when a dog is happy, it wags its tail. This only happens once your dog enters the REM cycle when it can dream. Happy dreams could be something like:

A memory of seeing you for the first time.

They are chasing a tennis ball or frisbee.

The dog made a new friend.

Another scenario of “sleep wagging” could be a simple case of they are just happy to sleep with you. But we will get into that later.

Usually, if a dog is having a good dream that makes it feel happy, you will be able to tell. There is more to it than your dog just wagging its tail while it is sleeping. It may also do these things when it is sleeping:

Vocalize with little yips or barks.

Look like they are running or jumping while they are still sleeping on their side.

They could even sleepwalk.

When you feel your dog is having a happy dream, do not worry about its tail wagging or all of the other signs. It is not a bad thing for them to have a good dream.

When you think of happiness and content, most people assume they are the same thing. But happy is a short-lived experience, while content is a long lasting experience. When your dog is content in their life, it is very likely that they will wag their tails in their sleep.

Generally, the signs of contentment are similar to those of just being happy. But if your dog easily falls asleep, and spends the night wagging away, then they most likely are completely content. Other signs could be:

They are quiet and relaxed.

A simple and serene sigh.

Their tail is high when wagging.

They are close to you while they are sleeping.

Contentment is a good thing, so there is really no reason to step in and wake them up from a dream they are having or the life that they are living.

Having A Nightmare

Dogs do wag their tails when they are scared.

But you’ll know for sure based on other behaviors exhibited, such as light barking, whining, crying, and heavy/rapid breathing.

Other causes of the dreaming tail wag may be anxiety caused by the subject of the dream.

The best thing to do is pet them gently and speak to them in a soothing voice. This should help calm them down and hopefully return them to a motionless state of sleep.

Why Is My Dog Wagging Its Tail Whilst Asleep? | DogVela

If you watch your dog long enough, you may notice him wagging his tail, barking, or moving slightly while he’s in a deep sleep.

This is actually common and usually a reaction to a dream. In rare cases, it may be a sign of a health problem.

Why do dogs wag their tails when sleeping? Dogs tend to wag their tails in their sleep when they are experiencing REM sleep. This is the part of the sleep cycle when dogs are in the deepest sleep. They wag their tails because they are relaxed and happy or while they are in the midst of a dream.

If you notice your dog is wagging his tail in his sleep and are wondering why, read on to learn more about this type of behavior.