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13 Surprising Reasons Why Dogs Sleep With Their Tongues Out

Why Do Dogs Sleep With Their Tongues Out

Your dog is having a nap when you notice something.

Their tongue is sticking out of their mouth.

You find it adorable, and you can’t help but admire the sight of it.

But… is this behavior normal?

And what could it mean?

Read on to find out:

  • Dog breeds prone to hanging their tongue when sleeping. 
  • Serious underlying medical issues that cause this behavior. 
  • 13 surprising reasons why your dog sleeps with their tongue out. 
  • And a lot more…

Why do dogs sleep with their tongues out?

Dogs sleep with their tongues out because they’re very relaxed, dreaming, dehydrated, or cooling down. They might also suffer from dental problems, breathing difficulty, hanging tongue syndrome, stress, poisoning, stomach distortion, or a side effect of new medications. Or due to genetics. 

The tongue-hanging behavior has been given an internet slang name.

Dog parents adore the look of their pooches when they sleep with a tongue hanging out. And they often take a picture of their dogs then post it on social media.

So, people from the Internet came up with the word ‘Blep’ to describe the behavior. It’s defined as the act of unconsciously leaving the tip of the tongue out of the mouth.

Blepping may occur due to a lot of factors. It may range from normal to serious reasons.

And here they are…

13 reasons why dogs sleep with their tongues out

#1: Your pooch is very relaxed 

Did your dog exercise before taking a nap?

Or did you play soothing music while they’re sleeping?

If yes, then maybe your pawed baby is too relaxed. Which may cause them to hang out their tongue.

This will likely be the case if your dog’s day has been busy. For example, they might have had a day full of playing, training, or even traveling.

All of these may tire your pooch. And being tired increases the feeling of relaxation during their sleep.

There’s a possibility that you may also hear them snore. Which is very common when dogs are having a good slumber.

#2: Your dog is dehydrated 

Dogs may also hang their tongue out when sleeping due to dehydration. 

So, try to think if your fur baby has been consuming enough food and water. And make sure that their water bowls are always full. 

Dehydration refers to a condition where dogs are:

  • Not consuming enough water.
  • Not having enough electrolytes.
  • Losing too much fluid in their body. 

This is common to happen in dogs. And may result in life-threatening conditions if not taken care of. Such as damage to a dog’s organ. In the worst-case scenario, death. 

Watch out for signs of dehydration in dogs and bring them immediately to the vet. Which include:

  • Lethargy.
  • Weakness. 
  • Collapsing. 
  • Sunken eyes. 
  • Dry and pale gums. 
  • Losing skin elasticity. 

Warning: Dogs may also be dehydrated if they refuse to eat or drink. Which may be a sign of other serious conditions such as:

  • Fever.
  • Diarrhea.
  • Diabetes. 
  • Heatstroke. 
  • Kidney problems. 
  • Other organ failures.

#3: Fido has dental problems 

How’s your dog’s dental health?

If there’s a problem with it, this may cause your dog’s tongue to hang out while they nap.

It’s likely to occur if dogs feel oral pain. Sticking their tongue out may help them to soothe what they’re feeling. 

The usual dental problem for dogs is cavities. But they may also suffer from other issues such as gum problems, a.k.a periodontal disease.

A study suggests that 85.3% of dogs may suffer from dental problems. 

VCA Hospitals says that periodontal disease affects about 80% of dogs. And usually occurs when they reach 3 years of age. 

Try to spot signs of dental problems in your dog. Which include:

  • Drooling.
  • Bad breath.
  • Losing teeth.
  • Visible tartar.
  • Difficulty eating.
  • Tooth discoloration.
  • Swelling under the eyes.
  • Fluid discharge from the nose.
  • Pawing at the mouth and teeth. 
  • Red, swollen or bleeding gums. 
  • Sudden weight loss or loss of appetite.

#4: Hanging tongue syndrome (HTS)

Dog Sleeps With His Tongue Out Due To Hanging Tongue Syndrome

Ever heard of hanging tongue syndrome?

If not, let me tell you about it. Because this might be the culprit for your dog’s behavior. 

HTS is a condition. It refers to when dogs are uncontrollably dangling their tongue out. 

This can be due to:

  • Injury.
  • Health problems.
  • Congenital defects.

Hanging tongue syndrome can only be diagnosed clinically. And it can also be treated. So, if you suspect your pooch has it, please bring them to the vet.

Here’s what you have to observe:

  • Bad breath.
  • Dry tongue.
  • Tongue bleeding.
  • Swelling of the tongue.
  • Thickening of the tongue.

#5: Breathing difficulty 

Does your dog breathe fast when they’re sleeping?

If so, that is a sign of having trouble breathing. Which may also cause blepping in dogs.

This will likely be the case if your dog is breathing faster than usual. And their breaths will also sound heavy.

Shortness of breath in dogs is called dyspnea. This may be due to several underlying medical conditions. Such as:

  • Pneumonia.
  • Chest injury.
  • Chest cavity.
  • Lung cancer.
  • Lung disease.
  • Heart disease.
  • Nose, throat, or diaphragm diseases.
  • Throat obstruction of foreign objects.

#6: Your fur baby is trying to cool down

Is it summertime already?

Or is it too hot in your dog’s sleeping spot?

If so, your pooch needs to cool down.

But here’s the thing:

Humans sweat when we feel hot, right?

How about when it comes to our canine companions?

They don’t sweat like us. Instead, they cool themselves down by panting. As well as sweating on their paw pads and nose.

So, what happens during hot days when your dog is trying to sleep? First, they might feel hot, which may cause them to have trouble breathing and cooling down.

As a result, they might hang their tongue out to cool themselves.

Now, you should prevent your dog from feeling too hot. Because overheating may lead to serious problems. Which can be caused by:

Heat stress

This refers to dogs who’ve been in a temperature of 104-106 degrees Celsius (219-223 degrees Fahrenheit) for a short time. Its effects on dogs are:

  • Lethargy.
  • Mild dehydration.
  • Difficulty in breathing.
  • Not able to cool off their body.


When the temperature is over 223 degrees Fahrenheit (106 degrees Celsius), that’s when heatstroke occurs. This causes a dog’s body to overheat. Which includes a dog’s skin, nerves, and other internal organs.

Heatstroke may also come with:

  • Diarrhea.
  • Drooling.
  • Vomiting.
  • Red gums.
  • Collapsing.
  • Excessive panting.
  • Loss of consciousness.
  • Uncoordinated movement.

Note: Some factors make a dog prone to overheating. These include:

  • Being overweight.
  • Having a thick coat.
  • Pre-existing heart disease.
  • Being a brachycephalic breed (A Pug or a Boxer, for example).

#7: Your pawed child is dreaming 

Did you know that dogs can dream?

Signs of it are when your dog twitches or whines during their sleep. Which you can probably see your pooch do once in a while. 

A study says that dogs and humans alike go through stages of sleep cycles. Which are:

  • Period of wakefulness.
  • Rapid eye movement (REM).
  • Non-rapid eye movement (Non-REM).

Dogs start dreaming if they reach the period of REM. 

The study focused on observing 6 pointer dogs’ brain activity. Results suggest that they’re alert 44% of the time, 21% half asleep, and 12% in the REM stage. And the 23% remaining was when they’re in a deep sleep of non-REM phase.

Now, your dog might also be dreaming if they’re blepping during their sleep. 

Let me tell you about Troy, my friend’s Beagle.

During the day, he’s fond of barking whenever he sees his dog friends.

So, at night or during his afternoon nap, he barks softly in his sleep.

One time, my friend slightly panicked when she heard Troy bark softly. It almost sounded like a mumbled bark.

But when she took a look at her sleeping pooch, he seemed to be just dreaming.

Your pooch’s case could be similar. It could be that they’re dreaming about eating or licking. That’s why their tongue sticks out when sleeping. This is because dogs often dream about what they do during the day.

#8: Mouth breathing 

Dog Mouth Breathing

Want to know a fun fact about a dog’s nose?

Dr. Nappier says that dogs can breathe in and out at the same time. Unlike us where we inhale and then exhale. We do it one at a time.

This amazing ability of dogs may also cause them to hang their tongue out while asleep.

Because they could be using the mouth breathing technique when they’re taking a nap.

Mouth breathing is when dogs use their mouth to take deeper breaths when sleeping. This is also a sign that your dog is sleeping peacefully.

Just like how humans do. Try to observe how someone sleeps. As their sleep gets deeper, they’re breathing gets heavier. Which sometimes causes their mouths to open and drool. 

Further reading: 9 Reasons Why Your Dog Is Breathing Fast While Sleeping

#9: Possible poisoning

Are you aware of what your dog has been putting in their mouth?

If not sure, there’s something you need to know.

Canines can be really curious and will taste anything they see. Which may happen when you’re not watching them.

What’s bad about this is your dog might get poisoned. Especially if they eat:

  • Garbage. 
  • Fecal matter. 
  • Dead animals. 
  • Raw or undercooked foods. 

Now, a dog who’s poisoned may hang their tongue out when sleeping. Since one of its signs is difficulty in breathing. They’ll hang their tongue out to breathe freely. 

One of the dangers is that it may lead to unconsciousness. 

Aside from that, difficulty in breathing may also come with:

  • Diarrhea. 
  • Lethargy. 
  • Vomiting. 
  • Dehydration. 
  • Reduced appetite. 
  • Lack of coordination. 
  • Seizures or collapsing.

Check out also: Why Does My Dog Drink So Much Water At Night? 15 Reasons

#10: Fido is in distress

Does your dog seem to be stressed lately?

If so, that could be the reason why the blepping when sleeping. Hanging their tongue out may help them soothe themselves. Or they might fall asleep while they’re licking as a coping mechanism. 

Try to think what could make your dog in distress. Some causes of their stress may include:

Your dog’s body language when they’re awake might also be your basis. For example, a stressed dog will exhibit behaviors such as:

Read next: 19 dangers (or when should you worry about dog panting)

#11: This is a side effect of medication

Is your pooch under medication?

If so, the tongue hanging behavior may be caused by it.

Dogs, just like humans, have different body reactions when it comes to medications.

Some may get the benefits of it without having to experience any side effects. While others may exhibit bad medication reactions.

One of the side effects of medication in dogs is tongue hanging. Especially if this is your dog’s first time to have it. Or their previous medication is suddenly changed. 

So, if you’re suspecting that this is the cause of Fido’s blepping, take them to the vet right away. Otherwise, this might lead to serious health problems. Such as stomach ulcers, kidney or liver problems.

Here are some of the other signs of medication side effects in dogs:

  • Diarrhea.
  • Lethargy.
  • Vomiting.
  • Weakness.
  • Skin irritation.
  • Lumps and bumps on the skin.

#12: Your pooch has stomach distortion

Stomach distortion may also cause tongue-hanging behavior when sleeping in dogs.

This stomach problem is commonly called bloating.

PetMD says that bloat is when a dog’s stomach stretches, which is caused by food or gas.

This results in rotating the stomach and traps the gas inside.

Wondering how it affects dogs?

This often reduces the dog’s blood flow and causes breathing difficulties.

That’s why when dogs are bloated, they hang their tongue out. This is to help them improve their breathing.

Some dog breeds are more prone to suffer from stomach distortion. Especially the deep-chested dogs, which include:

  • Akita.
  • Boxer.
  • Doberman.
  • Dachshund.
  • Bloodhound.
  • Basset Hound.
  • German Shepherd.
  • Doberman Pinscher.

#13: Your dog has a huge tongue

Dogs with a natural huge tongue may also be the reason why it sticks out when sleeping. 

This trait is due to a dog’s genetics. Some dog breeds have a longer tongue than others.

And brachycephalic dogs or short-headed dogs are known for that. Since they have flattened faces and short mouths, their large tongue won’t fit in it.

As a result, their tongue often dangles outside their mouth.

Note: Problems may arise when your dog’s tongue hangs out all the time. Such as:

  • Tongue drying.
  • Tongue cracking.
  • Dental and other mouth problems.

Examples of brachycephalic dogs include:

  • Pug.
  • Boxer.
  • Pekingese.
  • Chihuahuas.
  • Lhasa Apso.
  • Boston Terrier.
  • King Charles Spaniel.

Don’t miss out on: 9 Reasons Why Your Chihuahua’s Tongue Is Sticking Out