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Why Do Dogs Keep Smacking Their Lips? (Top 15 Reasons)

Portrait of funny dog smacking its lips after eating

As pet owners, we often wonder about the little things our furry friends do, such as why our dogs keep smacking their lips.

While occasional lip-smacking in dogs seems normal, excessive lip-smacking can be troubling.

Lip-smacking in dogs can be due to several reasons, such as food anticipation, stress, or simply an attention-seeking habit. Other underlying causes that need serious attention are allergies, dehydration, poisoning, and dental, digestive, and neurological illnesses.

In this guide, I listed the top 15 reasons for dog lip-smacking. To learn more about why dogs do this and understand them better, keep reading until the end!

Why Do Dogs Smack Their Lips?

Happy Chihuahua dog smacking lips

Dogs smack their lips due to a number of reasons. They do this by opening and closing their mouths loudly, which often involves licking their lips as well. 

While some reasons can be considered normal bodily reactions, there are instances where lip-smacking is an indication of something more serious.

Below are the top 15 reasons for dog lip-smacking: 

1. Anticipation of food and treats

When dogs smell food or anticipate getting treats, many dog owners notice their pooches lick their lips.

This is considered a normal behavior as the smell and thought of food signal the dog’s salivary glands to prepare to digest food.

They can sometimes get excited about eating and, to prevent themselves from drooling, may instinctively resort to lip-smacking. In this case, dog-smacking lips behavior is not a cause for worry.

It’s simply their way of expressing enthusiasm over getting something satisfying and tasty.

2. They finished a meal

After finishing a good meal, some leftover food may be stuck inside the dog’s mouth. This can cause dog licking and dog-smacking lips behavior.

Your pooch may be trying to remove the food particles stuck between its teeth or gums as a form of hygiene practice. As a result, you’ll hear or see your dog smack his lips.

Similar to food and treats anticipation, this behavior is not a cause of alarm when done after eating.

3. Hair inside the mouth

When they explore and play, many foreign objects can get inside your dog’s mouth, including its own hair. This also happens when they clean themselves or lick their fur.

Long-haired breeds like the Jack Russell Terrier and Corgi can be more susceptible to this.

As such, you can notice dog-smacking lips behavior from your furry family member when they try to remove the hair inside their mouth. 

You can help your pooch by checking its mouth and taking out any hair or object that may be stuck between the teeth, gums, or tongue. 

This will help relieve the discomfort it may be feeling and cease the constant lip-smacking.

4. To soothe stress and anxiety

Dog-smacking lips behavior can also be due to stress and anxiety. When a dog is afraid, nervous, or experiencing any emotional distress, it may smack its lips repeatedly as a stress-coping mechanism.

From a perspective of a dog behaviorist, this can be identified as a pacifying or appeasement behavior.

When your canine does this, it is trying to express that they are not a threat and have no desire to start a fight.

Your dog may feel stressed when being scolded, hearing loud noises, encountering aggressive dogs, and being in an unfamiliar environment.

To help them calm down, remove them from the stressful environment, or divert their focus to other activities like playing with their favorite toy.

You should also avoid punishing your pooch whenever it misbehaves. Applying positive reinforcement can teach and motivate them to perform the desired behavior.

Notice how the dog licks and smacks its lips when it feels stressed in the video below:

Identifying Canine Anxiety (Tongue Flick/Lip Licking)

5. Reaction to pain

Dog-smacking lips behavior is done by many canines as a way of soothing themselves whenever they are injured or experience pain. 

Pain can cause them to be extremely uncomfortable and anxious. Thus, they smack and lick their lips to soothe themselves. 

When there is a persistent ache, it is often accompanied by excessive licking of the painful area. 

This is common among large breed dogs with hip dysplasia, as the pain causes them to lick the affected leg constantly. Affected breeds are usually Saint Bernards, German Shepherds, and Labrador Retrievers.

Pay close attention to the area your pooch is constantly licking as this may be the body part affected by an illness or where it had been injured.

6. Dreaming

Lip-smacking in the middle of the night can be caused by dreaming. When you observe your dog licking its lips in the middle of the night while being fast asleep, it may already be in dreamland, visualizing its daily activities.

In their REM sleep phase, dogs are able to dream like us humans. During this phase, dog licking and lip-smacking are often accompanied by twitching, murmuring, or barking.

They may be dreaming about eating their favorite treat or reliving the stress of meeting an aggressive dog in the park.

Since they can also have nightmares, it is advisable not to wake them up during this time as this can be disorienting for the dog. Touching your pup suddenly may also cause it to accidentally bite you.

It is better to allow them to wake up on their own and comfort them or call their name out loud to wake them up instead of touching them.

7. Dehydration

There are also times when dogs smack or lick their lips in the middle of the night due to dehydration. They are more susceptible to dry mouth smacking during summertime when the weather is scorching.

When this happens, the dog’s salivary glands are affected, resulting in thick and pasty saliva. Other symptoms of dehydration include loss of appetite, sunken eyes, dry mouth, dry gums, and dry skin. 

Extreme cases of dehydration may require IV fluid therapy to normalize the water content of the dog’s body and prevent serious damage to the kidneys and other organs.

It is best to provide enough drinking water that is easily accessible to your pet at any time. Make sure that they are also able to replenish their fluids after intense play or exercise.

If your pooch isn’t fond of drinking water, you could wet its kibble to add moisture. You can also feed your pup ice cubes to help it cool down and increase water intake.

8. Mouth diseases

Periodontal disease and other mouth diseases can also cause discomfort and lead to dog-smacking lips behavior. 

When dogs suffer from periodontal disease or canine gum disease, the build-up of bacteria brings about gum irritation and swelling. It also damages the teeth and soft tissues surrounding them.

Another mouth disease resulting in lip-smacking behavior is canine stomatitis. Symptoms of canine stomatitis include mouth pain, bad breath, receding gums, and mouth sores.

Meanwhile, dogs with mouth cancer that are undergoing cancer treatment can also experience similar symptoms of mouth diseases like mouth sores, redness, and swelling.

As pet parents, it is important to take care of the oral health of your pooch through regular brushing and dental appointments to avoid developing these mouth diseases and save your pooch from pain and uneasiness.

9. Allergies

Dog-smacking lips behavior could also be a sign of an allergy. Many dogs that have food allergies may experience itchy skin and ear infections. Raised bumps on the dog’s tongue, lips, and throat can also be noticed.

The usual culprits of food allergies are protein derived from dairy, soy, wheat gluten, chicken, and beef. And when a dog is allergic to this, it is likely that they’ll smack or lick their lips to soothe the irritation.

A vet can carefully examine your pet’s history and run tests to determine the cause of the allergic reaction.

Meanwhile, to be on the safe side, look for dog food and treats that are free from common allergens.

10. Due to nausea

Dog lip-smacking can also be due to nausea. When a dog is feeling nauseous, it causes the salivary glands to produce excess saliva, and as a result, the dog licks and smacks its lips to prevent drooling.

Usually, a dog vomits because it may have eaten too much food or eaten too quickly. At times, eating grass also induces vomiting in dogs. 

When your dog repeatedly vomits, a trip to the vet may be necessary as this can lead to dehydration and extreme weight loss. 

In addition, chronic vomiting could be a sign of more severe health issues such as bloat, bacterial infections, pancreatitis, and heat stroke.

11. Upset stomach

Another reason for lip-smacking behavior is an upset stomach. There are several causes of an upset stomach, one of which is bilious vomiting syndrome

This syndrome occurs when bile enters the stomach resulting in the irritation of the stomach’s lining. As this usually happens early in the morning or late at night, the dog vomits on an empty stomach.

A likely cause for bilious vomiting syndrome is going on extended periods without food intake, which mostly affect dogs that are only fed once a day. 

The recommended treatment for this syndrome is a more frequent feeding schedule, which prevents the dog’s stomach from going on long hours without food to digest. Treating this sickness is crucial as it can lead to acid reflux.

When a dog suffers from acid reflux or gastroesophageal reflux disease (GERD), the stomach acid rises from the stomach to the esophagus, irritating the dog’s esophagus.

High blood calcium, obesity, and eating spicy foods are some of its causes.

Along with dog-smacking lips behavior, other symptoms of acid reflux are chronic cough, decreased appetite, and bad breath.

Meanwhile, inflammatory bowel disease is another cause of lip-smacking in dogs. Canines affected by this disease also experience diarrhea, flatulence, and weight loss.

While the exact reason for inflammatory bowel disease is unknown, this usually happens when the dog has a parasite infection, allergy, or hypersensitive immune system.

12. Ingestion of toxic substance

Ingestion of a toxic substance is a serious issue that needs to be immediately addressed. 

When you notice lip-smacking behavior from your pooch and suspect that it may have accidentally swallowed poisonous food or chemicals, contact your vet as soon as possible.

Aside from lip-smacking, you might notice other signs of poisoning like excessive drooling, nausea, and in some cases, burns in the dog’s mouth.

Find out the specific substance that your pooch has swallowed. If possible, take a sample, label it, and bring it to your vet for analysis. 

Never induce vomiting without consulting your vet. You can also contact Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661 to get additional information and guidance.

13. Nervous system disorder

There are instances where lip-smacking is due to a nervous system disorder. In cases of canine cognitive dysfunction syndrome, the dog experiences confusion, anxiety, difficulty in learning new tasks, and loss of appetite.

Affected pets may also exhibit other symptoms which can be considered unusual behavior, like excessive barking, incontinence, and irritability. 

Canine cognitive dysfunction is usually an age-related health problem seen in adult dogs and is particularly common among senior dogs. 

Another neurological health issue is canine obsessive-compulsive disorder (OCD). Similar to humans, when dogs have canine OCD, they perform normal tasks and activities repetitively and excessively.

If you notice your dog lick or smack its lips repeatedly, chew its toy nonstop, or chase its tail obsessively, these may be signs that it has canine OCD. 

With that said, it is advisable to seek the professional opinion of your vet to properly diagnose this disorder.

14. Kidney disease

Kidney disease can also trigger lip-smacking in dogs. This can be a sudden severe illness or a long-progressing disease, depending on the cause. 

Ingestion of a toxic substance, bacterial infection, heat stroke, and periodontal disease are common reasons for kidney disease in dogs, which is similar to liver disease.

Other known causes of kidney disease are urinary tract infections, kidney stones, and dehydration.

Aside from smacking their lips excessively, bloody urine, extreme thirst, weakness, and weight loss are signs of kidney disease. You will also notice that the dog’s gums are looking pale.

Untreated kidney disease can be fatal in canines. Often, this disease requires immediate hospitalization for proper treatment to avoid end-stage kidney failure.

15. Attention-seeking behavior

Lip-smacking can also be a manifestation of your pet’s attention-seeking behavior.

You may have unknowingly reinforced this habit when you gave your pooch attention the previous time you noticed a lip-licking behavior from it.

And as your pooch learns to use this technique to get attention from you, it may lick and smack its lips constantly whenever it wants to get noticed. 

As dog owners, try to validate your pet’s attention-seeking habit. A healthy dog that smacks its lips excessively is showing signs of a behavioral problem that may be rooted in boredom, lack of mental stimulation, and exercise.

You might have also been neglecting your quality time with your dog, which is why it is resorting to lip-smacking. 

Find time to show more affection towards your pooch and make sure that it is getting enough daily exercise and mental stimulation

When to See the Vet for Dog Lip Smacking

Hungry dog smacking its lips

Lip-smacking can be an urgent concern when you notice your dog exhibiting abnormal behavior aside from licking its lips excessively. 

If you observe other signs such as frequent vomiting, loss of appetite, diarrhea, chronic cough, or even unusual change in its temperament like showing unnecessary aggressive behavior, it is time to seek your vet’s help.

Likewise, lip-smacking behavior due to suspected poisoning also warrants an emergency trip to the vet.

As lip-smacking is often a sign of a health problem, it is important to pay attention to the symptoms that accompany this behavior. 

Being vigilant and cautious help to ensure our canines grow and remain to be healthy dogs for a very long time.

Frequently Asked Questions

Dog laying on the stairs and smacking lips

Why Do Dogs Smack Their Lips Before Sleeping?

To some pet parents, lips-smacking before sleeping might seem like strange behavior, but for dogs, this can be a soothing and relaxing habit.

Thus, when they try to fall asleep, the dog smacks its lips as a comforting and calming experience.

But if you observe that your pooch appears anxious, nauseous, or excessively drooling before going to bed, these are signs that something’s wrong and must be further looked into.

Why Do Dogs Smack Their Lips at Night?

Dreaming and anxiety can cause your pooch to smack its lips in the middle of the night.

However, if this behavior is displayed along with loss of appetite, vomiting, thick saliva, and dry mouth, it could be a sign of an illness.

Possible causes of dog-smacking lips in the middle of the night are dehydration, mouth disease, and stomach upset. In some cases, this can also be a sign of kidney disease and nervous system disorder.

Why Do Dogs Smack Their Lips When Lying Down?

When you see your pooch smacking its lips when lying down, it could be doing it to soothe its anxiety, or it might be nauseous.

Excessive lip-licking when lying down is a cause for concern because serious illnesses can be the reason behind this unusual behavior. 

Always check for any indication of a tooth infection, signs of dehydration, or allergic reactions whenever you see your dog smacking its lips when lying down. 

Why Do Dogs Smack Their Lips When Petted?

Since not all canines enjoy being petted, you may notice your dog smacking its lips when you’re petting it. This is a sign that they are not at ease with your actions and may be anxious or tense.

Its lip-smacking may be a way to soothe nervousness. In situations like this, it is advisable to cease petting your dog and let it calm down. 

While it is natural for us to want to hug and pet our dogs, for some dogs, this is interpreted as threatening behavior.

Let them approach you naturally and show you will not harm them by giving light and gentle strokes.

Why Do Dogs Smack Their Lips After Eating?

After eating, lip-licking and lip-smacking behavior can often be seen in many dogs because they may still have some food left in their mouths.

Other reasons why dogs lick and smack their lips after eating are when it is experiencing acid reflux or feeling nauseous. Your dog will noticeably be smacking its lips excessively during this time.

Final Thoughts

As dog owners, you always want your dogs to be happy, healthy, and comfortable, which is why it can be worrisome when you notice frequent lip-licking and lip-smacking behavior.

Since they cannot directly tell you how they feel, you must pay attention to the other cues and symptoms that reveal the reason why dogs lick and smack their lips.

Hopefully, this guide has enlightened you and helped you better understand your pet’s behavior. The next time you see your dog smacking its lips, you will be able to better determine the reason behind it.

At the same time, you can now be more watchful of specific symptoms that need immediate care and attention.

Have you noticed this behavior in your dog? Comment down below if you have noticed your dog smacking lips!