Dog Smacking Lips In The Middle Of The Night (Possible Causes)

There could be a number out why your dog is smacking his lips in the middle of the night.

Lip-smacking in dogs is an instinctual behavior, but it could point to issues in other areas in his life.

A typical dog learns licking behaviors in puppyhood from their mothers. Their mothers usually lick them when they’re young so that urination and defecation can be stimulated. This is also her way of grooming them.

You will sometimes see dogs licking each other or dog licking humans. This is a normal part of their social interaction, and it can also be soothing to them.

Dogs are different from humans because they don’t have to explore the world with touch. They must rely on their tongues and noses to understand and learn their surroundings. 

They have an acute sense of smell, and they tend to lick things that taste good or have a pungent smell.

Not only that, but they may also lick objects because they are bored stressed, or nervous.

However, licking may be a sign of something wrong with your dog and this is where you must pay close attention. Sometimes your dog may have an allergy that causes him to lick himself because he feels itchy.

Why Is My Dog Smacking His Lips?

Dogs Smacking Lips

Dogs frequently lick and smack their lips and this action is sometimes the way they communicate.

Sometimes they may be licking the drool that is dripping down from their face when they are in the presence of food. Or they lick their lips after they have just eaten and are satisfied.

Sometimes they may be licking their lips constantly to get rid of a disgusting taste. Dogs may also have a personal quirk where they lick their lips all the time and this is perfectly harmless. Dehydration is also another reason why your dog may be licking their lips constantly.  

These are common reasons why your dog may be smacking his lips:


Your dog can have nausea for several reasons like eating too quickly or eating something toxic. If he has an upset stomach he can sometimes vomit so that the excess pressure on the abdomen can be alleviated.

Before vomiting takes place, there is sometimes saliva in the mouth. This saliva forms so that the throat and mouth can be protected from stomach acid that is brought up with the puke.

This can be the reason your dog smacks his lips. It is a physiological response from excess saliva that is accumulating in his mouth before he vomits.

If you think that your dog is about to vomit then you should get him to a place where it is better to do so like the bathroom when clean up is easier.

After the vomiting episode, you can provide clean cool water for your dog to drink. This will help to relieve some irritation going on in the stomach.

If your dog vomits only one and is okay after he has done this, and is not smacking his lips anymore, then you can consider the worst to be over.

However, if he continues to vomit then he should be taken to the veterinarian as soon as possible. 

Sometimes hunger can cause nausea in your dog because gastric acid is accumulated in an empty stomach leading to fluid movement in the esophagus.

When this happens your dog has irritation in the mouth and throat causing him to lick his lips a lot. You may also see him swallowing and having hiccups.

To avoid hunger it is better to split up your dog’s meals into different feeding times and make sure that they have a late evening snack to prepare for the time where they will not be eating.  

Food Anticipation

Mammals tend to salivate whenever they smell food, so you can expect this to happen to your dog.

Your dog may have a physiological reaction to the smell of food like meat cooking or opening a commercial dog food bag. Licking the lips is simply a way of not dribbling all over the place. 

As the saliva pools in their mouth because of anticipation, he is likely to smack his lips and move his tongue laterally so that the saliva does not leave his mouth.

This reaction is totally normal and as long as you feed your dog you will notice that it stops.

Dog Food With Salmon

Dr. Ivan Pavlov has conducted important studies on classical conditioning to show how dogs respond to stimuli. The research has been used over the years and is still used today.

He observed that dogs would begin to salivate as soon as they saw the people who usually feed them.

The dogs even recognize certain movements that are used when it comes to someone feeding them.

If you have ever been in a restaurant and saw your server coming out with the food you might automatically begin to salivate.

You may respond with excitement, or you may begin to swallow that extra saliva. It’s the same with dogs as they may jump up and down and start barking while smacking their lips with excitement.

If you train your dog, and you give them treats to reward them, they may begin to salivate as soon as they complete specific commands.

If you use a clicker device your dog may begin to salivate as soon as the clicker sound is heard. All of these are reasons why they smack their lips in the presence of food. 

Acid Reflux

Just like human dogs make go through acid reflux especially when they are small breeds with high metabolisms. Gastric fluids usually go into the empty space when they have not eaten.

Then the intestinal fluids travel up into the esophagus from the summer leading to inflammation and irritation. Your dog will produce saliva and lick his lips to ease the irritation.

If your dog is healthy, then his sphincter muscle which is located at the bottom of the esophagus opening will be closed. This muscle stays closed so that fluids can’t enter the esophagus.

In smaller breeds and sometimes older dogs this muscle does not function properly and becomes loose. If this occurs then you need to take your dog to the veterinarian so that medication can be prescribed for acid reflux.

Object Embedded in Mouth

There may be sometimes objects embedded in your dog’s mouth causing him to lick constantly. Puppies and dogs in general typically like to sharpen their teeth by biting on stray objects.

Sometimes it is a fun game when they go fetch other items based on your instruction. Your dog may get something lodged in his mouth while biting down on one of these items.

If you believe that this is the case then try your best to examine your dog’s mouth for foreign objects.

In some cases it’s will be easily removed with your hands but if it is stuck to gum areas or the roof of his mouth, and then it might be wise to take him to the veterinarian where they can remove it’s properly. You do not want your dog to bleed out.

Additionally, insects can become stuck in your dog’s mouth some of which are venomous. This can be toxic to your dog and call him to produce excess saliva, and you will see him licking his lips a lot.

To get rid of foreign objects, your dog may also scratch at his face or choke in an attempt to get rid of the object that is stuck.

Periodontal Disease and Dental Issues

Dental problems may also cause your dog to keep smacking his lips. These dental issues should be taken seriously and addressed properly. Remember that dogs also need frequent dental care. 

This could be as simple as brushing his teeth once per week. You should also have oral exams done on your dog by a veterinarian. The vet will look for excess plaque along with gum irritation and broken or loose teeth.

The vet can also perform teeth cleaning similarly to the dentist, but dogs require anesthesia so that it’s can be safely done.

Remember left your dog would be unable to communicate with you that their gums are sore, or the teeth are broken so drooling and smacking their lips is the only thing they can do.

You may also see them scratching their mouth with their paws. If you notice these behaviors then pay special attention and if you are unable to figure out the problem then take him to a vet. Canine gum disease is a serious concern that affects many dog breeds, but many dog owners miss it.


Xerostomia is the opposite of Sialadenosis because this is when your dog has a dry mouth. This can be very uncomfortable for your dog because when not enough saliva is produced by the salivary glands your dog can smack his lips a lot.

And healthy dogs this is quite uncommon what’s older dogs often suffer from this. Dogs who have cancer and are undergoing cancer treatment are more likely to have this condition.

As a dog parent, you can encourage your dog to wash his mouth find to give him extra fluids.


On some occasions, your dog can develop a condition where his saliva glands become infected and swollen listening to saliva accumulating in the mouth.

This condition is called Sialadenosis.  your dog will smack his lips to move around the saliva and reduce excessive drooling.

In a dog, the saliva glands are right beneath the tongue. If you open your dog’s mouth and look beneath the tongue and notice swollen lumps then visit your veterinarian as soon as possible. Medication can be prescribed for this condition. 

Canine Stomatitis

Canine stomatitis is another mouth disease that can cause your dog to smack his lips.  Canine stomatitis is a condition where your dog has inflamed mucous membranes in his mouth.

This would cause sores to develop on the gum line, and he will have swollen gums. There will also be sores on the inner lips.

Dog Smacking Lips Causes

Any dog breed can be affected by this condition, but it is more likely to affect greyhounds, Labrador Retrievers, miniature schnauzers, and Malteses.

The condition it’s caused by a dysfunction in the immune system causing the gum to respond severely to plaque. You need to take him to regular dental exams with your veterinarian.

Liver and Kidney Disease

In older and middle-aged dogs, you may notice that they suffer from diseases affecting their liver and kidneys.

They may develop symptoms such as frequent urination and larger consumption of water. Renal failure occurs when the body is unable to efficiently eliminate waste and clean the blood.

You may notice that your dog licks his lips and is nauseous when he has developed kidney disease. You may even notice some vomiting stop.

In older dogs, the symptoms are much more pronounced, and you should visit your veterinarian who will formulate a course of action.


It is very easy for a dog to become dehydrated especially in hot dry climates. They may lose water even faster when they suffer from kidney or liver disease.

They will smack their lips excessively when they are dehydrated to wet their mouths and make it more comfortable.

If you notice that’s your dog appears depressed and his skin has lost elasticity this could mean that he is dehydrated. You may also see dry and peeling gums along with crusty scabs on his mouth.

His gums may also be sticky. It is crucial that your dog is rehydrated as soon as possible.

To do this you need to change as water frequently like once per day. Try to implement water in his food by giving him wet food as opposed to dry kibble.

Your dog will have to undergo IV fluid therapy in more severe instances of dehydration.

Reinforced Behavior

Sometimes when your dog is smacking his lips it has nothing to do with a medical condition font with the attention he receives when he is smacking his lips.

This causes reinforced behavior so that whenever he wants your attention he will smack his lips, and thus he continues this Behavior.

Whenever you reinforced this behavior it makes the habit even stronger, and it encourages him to smack and lick his lips all the time.

In order to stop this, you should ignore the lip-smacking of your dog and reward other behaviors so that he will not be rewarded with your attention.

Remember that you should not punish him for smacking his lips as this may do more harm than good. Also, consider speaking with a dog behaviorist who can provide more advice about eliminating this Behavior.

Emotional Distress

When your dog is going through emotional distress they may smack their lips. just like humans do dogs go through fear, confusion, and discomfort.

Your dog may feel a range of emotions depending on their environment or events surrounding them such as sudden loud sounds, thunderstorms, all being pads by strange people.

Look out for your dog entering a crouched position and being tense when they are uneasy in any way. They may also lower their ears and suck their tails. Many dogs avoid eye contact and hide in places they deem safe.

You can reduce anxiety in your dog by making sure that they exercise every day giving them toys that would occupy their mind. You should seek advice from your veterinarian if your dog is severely distressed.

When To Be Concerned About Dog Lip Licking

My Dog Smacking Lips

There is often a medical reason when your dog is smacking his lips excessively. If you find that your dog is smacking his lips more than usual then seek the help of a vet if there is no reasonable explanation for his behavior.

You should take special care of senior dogs when you notice they are smacking their lips as they are more at risk for harmful diseases.

Understand that when smacking lips goes along with nausea, diarrhea, vomiting, drooling, weight loss, and appetite change then there could be a serious issue, and you need to get your dog checked out by a professional.

To help the veterinarian understand see all dogs change in behavior you can take videos or pictures so that a better diagnosis can be made.

Your veterinarian will most likely conduct a series of exams and tests. He may most likely acquire blood fecal and urine samples so that these tests can be done. Your job might also need to do a neurological exam. If no conclusive diagnosis can be made then your veterinarian may suggest behavioral therapy.

Final Words

If your dog only smacks his lips in the middle of the night then it may be because of nausea or dehydration. Ensure that your dog has access to water at all times.

And to prevent nausea due to hunger you should give your dog a late-night snack.

Apart from this, there may be many other reasons that your dog is smacking his lips. The important thing would be to monitor closely and then take the information to your veterinarian for help.

Remember that if your dog is smacking his lips at night, then he is not sleeping. This lack of sleep can also affect him and deteriorate his health. This is why if the situation persists is can have serious consequences.

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