If you see a dog licking his lips, you might assume he is simply eating or drooling over something. But what if there is no food around? What does lip licking mean then?

Lip licking is a type of dog communication. A dog who licks his lips is using body language to let you know how he's feeling.

What Is Lip Licking in Dogs?

Lip licking is just what it sounds like: a dog licking his lips. If you notice a dog is licking his lips when there's no food involved, he's probably trying to send a message.

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What It Means When Dogs Lick Their Lips

Dog trainer and behaviorist Turid Rugaas coined the phrase "calming signals" to refer to lip licking and similar dog behaviors. Lip licking is also often referred to as an appeasement gesture. Dogs exhibit certain behaviors and actions when they feel stressed or uncomfortable. It's usually because there is something going on around them that they perceive as a threat. Dogs who are licking their lips are usually sending the message that they are worried.

Dogs lick their lips to appease and soothe a person or animal they see as a threat in order to ward off aggression. An example of this can be seen in dogs who are scolded when their owners return home to find the dog has had an accident in the house. A dog might not connect the scolding to relieving himself indoors. Instead, he sees his owner as a threat. The owner may be yelling and looming over him. The dog may offer an appeasement gesture by licking his lips and averting his gaze. This is the dog's way of saying that he isn't a threat to the person behaving in an aggressive manner.

Sometimes dogs exhibit appeasement gestures like lip licking and yawning when they are frustrated or confused. Many owners notice this during training sessions when their dogs are having trouble understanding what is being taught. If you notice lip licking, yawning, scratching, or ground-sniffing while training your dog, it might be time to stop the training session. A dog cannot learn new things when stressed. To end on a positive note, ask your dog to do something simple he already knows, like sit. Reward with a treat and praise, then end the session. Try playing with your dog for a little while to bond and help your dog relax.

Another important possible reason for excessive lip licking in dogs is a health-related issue. A dog might lick his lips due to nausea, dental disease, or mouth pain. Look for other signs of illness and keep a close eye on your dog. When in doubt, contact your vet.

Illustration: Vin Ganapathy. © The Spruce, 2018

What to Do if Your Dog Is Licking His Lips

While lip licking is usually considered a submissive gesture meant to prevent aggression from escalating, it is still a sign that a dog is stressed and uncomfortable with a situation. This appeasement gesture could be the dog's first attempt to remove the threat, like to stop his owner from yelling at him or to get another dog to stop barking at him. However, this doesn't mean that the dog won't become defensive if the perceived threatening situation continues. A defensive dog may resort to aggressive behavior if appeasement gestures are unsuccessful.

If you see a dog licking his lips, back off and allow him some space to get more comfortable. Try to determine the source of the dog's concern and remove it, if possible. This can save you from a potential bite from a dog who feels the need to defend himself.

If your dog is lip-licking at the vet or another place that makes him nervous, try to redirect him in a positive manner. You can ask him to do a trick and then reward him for complying. Avoid comforting your dog when he is uneasy as this only reinforces his fear or anxiety.

If your dog is lip-licking during a training session, it's probably best to find a way to quickly end on a positive note (ask your dog to do something he knows and wrap up the session). Next time, break down the action or behavior into smaller segments so it's easier for your dog to learn. This is sometimes called shaping behaviors.

If you often find your dog exhibiting lip-licking behavior when there is no clear threat and no food around, you may want to investigate further. Perhaps there is something in your dog's environment that is making him uneasy. Remember that there may even be a health problem, such as nausea or oral discomfort. When in doubt, take your dog to the vet for a check-up.