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Why does my dog wag his tail when he sleeps?

Few things are cuter than a dog sleeping. You may have noticed your dog wagging their tail in their sleep. They may also kick their feet, bark, or whine when sleeping. 

Why does my dog wag his tail when he sleeps?

Your dog seems to be asleep, but they are wagging their tail. It can leave you wondering what is going on in their mind. Why do they wag their tail when sleeping? 


Dogs wag their tail when they are sleeping because they are dreaming. It’s thought that dogs dream similarly to humans. Of course, it’s difficult to know exactly what happens when dogs dream. Humans can discuss their dreams when they wake, but you can’t ask your dog what they were dreaming about. 

Dreaming occurs during REM sleep. Essentially, pathways in the brain activate during sleep, paralyzing the body to prevent movement. This is why you, or your dog, don’t get out of bed and run when you are running in your dreams. 

However, in humans and dogs, this mechanism isn’t perfect. Occasional movements happen. The most likely reason your dog is wagging their tail in their sleep is something occurring in a dream that evokes a tail wag. 

What a Wagging Tail Says

The misconception that a wagging tail always indicates happiness can lead to miscommunication. Dogs do wag their tail when they are happy, but this isn’t the only reason. 

Dogs are social animals, which means communication is essential, just as it is for us. Instead of expressing themselves with words, they have a wide variety of other communication methods. One of these is the tail wag. 

The “happy tail wag” is the one every owner loves to see. The tail will be held in a neutral or slightly raised position. The dog appears relaxed. The faster the tail wag, the more excited the dog is. 

When your dog holds their tail straight up or over the back, this indicates aggression. It exposes the anal glands, which are used for scent communication. The tail may wag, but this isn’t a happy gesture. It’s a warning, similar to the rattle of a rattlesnake tail. 

On the opposite end of the spectrum is submission or fear. A dog with its tail pointing down is showing submission. If the tail is tucked between the legs, the dog is scared. The anal glands are covered. This is the dog’s way of retreating into the shadows, saying “don’t mind me”. 

The speed of tail movement also holds clues. Just as a fast wagging tail indicates excitement, a slow wag indicates uncertainty. A dog that is slowly wagging its tail isn’t quite sure about the situation. 

Do Breed and Age Affect How Dogs Dream?

Puppies dream more often than adult dogs. Puppies and elderly dogs are more likely to twitch or make noises while dreaming than adult dogs, probably because the paralyzation pathways are not as strong as they are in adult dogs. 

It’s not necessarily breed, but size that plays a role in how dogs dream. Small dogs tend to have shorter dreams that occur more frequently. Larger dogs have longer dreams but don’t have as many dreams. 

This can help give you perspective if you notice your dog having a nightmare. A small dog will quickly move on from the dream. Large breeds may have dreams for as long as five minutes.

Should You Wake a Sleeping Dog? 

If you notice your dog with its tail tucked during sleep, you may wonder if they are having a nightmare. It’s believed that dogs can have pleasant and unpleasant dreams, just like we do. Some dogs will even whine in their sleep when having a nightmare. This raises the question, should you wake a dog having a nightmare? 

It’s best to let sleeping dogs lie for a few reasons. The first is safety. When you are awakened from a deep sleep, you are temporarily disoriented. It can take a few minutes to remember where you are. The same is true for your dog. If you wake them from a nightmare, they may bite before they realize they are no longer in their dream situation. 

The second is because REM sleep is essential for your dog’s health. When sleep cycles are disrupted, it lowers the overall quality of sleep. Your dog may have difficulty going back to sleep, and miss out on important time in deep restful sleep. 

Do dogs pretend to sleep?

Have you ever pretended to be asleep? Maybe you just weren’t ready to get out of bed, or you simply didn’t want to answer the phone. Children often pretend to be asleep so vigilant parents will let down their guard. You may find it surprising that dogs are capable of this as well, for similar reasons. 

Pretending to Sleep

Do you notice your dog seems to go to sleep whenever you mention something unpleasant like a bath or a trip to the vet? You may find yourself wondering if they are actually asleep, or simply faking it. 

Dogs may also pretend to sleep for the same reason children do. When you think they are asleep, you assume they won’t get into any trouble. Your guard is down, and you aren’t watching them as closely. 

When a dog is pretending to sleep, you may notice that their body language suggests they are alert. Their ears may be perked, indicating that they are listening. One or both eyes might be slightly open, so they can see what is going on around them. 


It can be difficult to distinguish between a dog that is pretending to be asleep and one that is dozing. Just like humans, dogs can enter a half-awake state that allows them to rest while still maintaining an awareness of the world around them. Because they aren’t completely asleep, they will have alertness similar to a dog faking sleep. 

How Can You Tell If Your Dog is Faking It?

One of the simplest ways to see if your dog is faking it is to mention something they enjoy. If your dog seems sound asleep, but is instantly awake at the mention of a walk, chances are they were faking sleep. 

However, it’s important not to disturb dogs that are actually sleeping, and some dogs are light sleepers. Determining if your dog is faking it requires observation and following your instincts. 

Why does my dog wag his tail when he lays down?

Why does your dog wag their tail when they lay down? Are they simply happy to have a comfortable spot? Or could there be more to it?


It’s likely your dog wags its tail when laying down out of simple happiness. Perhaps they are laying in a comfortable bed or their favorite spot on the floor. If they wag their tail when laying down next to you, it’s a sign of affection and contentment. 

Moving Tail Out of the Way

Dog’s tails are sensitive. Just like the rest of their body, the tail has pain and nerve receptors. Laying on their tail can be uncomfortable, so they may wag their tail to ensure it’s out of the way before laying down. 


If your dog is wagging their tail and looking at you while laying down, it’s probably a request for attention. It might be their way of saying, “pet me”. They may also be bored and looking for some stimulation. 

Checking Their Tail

Your dog may wag their tail when laying down to ensure it is still there. They can feel the motion of their tail, which lets them know that it is safe and functional. It’s difficult for a dog to look back and see their tail, so it’s easier to feel it moving instead.