Dogs lick their lips after eating, and around food. That is the version everyone recognises.
Repeated lip licking with no food involved is a different signal, and it is one of the more useful ones a dog gives.
Nausea
The most common medical cause. Lip licking is often the first outward sign, appearing before any vomiting.
The cluster to look for:
- Repeated lip licking and swallowing
- Drooling, sometimes with stringy saliva
- Eating grass, or licking hard surfaces
- Turning away from food
- Restlessness, then settling, then getting up again
If those appear together, the dog is feeling sick even if nothing has come up. A dog that then vomits repeatedly, or that has a swollen abdomen, needs a vet.
Stress and appeasement
Lip licking is a well-documented calming signal — a way dogs communicate that they are uncomfortable and mean no harm.
It rarely appears alone. Look for it with:
- Yawning when not tired
- Turning the head away
- Whale eye — the whites of the eyes showing as the dog looks sideways
- A low or tucked tail, ears back
- Freezing, or moving away
Common triggers: being hugged, a stranger leaning over, a child's face close to theirs, being told off, the vet, or another dog approaching directly.
This matters beyond the dog's comfort. Lip licking during an interaction is one of the earliest warnings a dog gives before escalating, and it is one of the most commonly missed. Giving the dog space at this point prevents nearly everything that would come later.
Dental and mouth pain
Very common and easy to overlook.
- Dropping food, or chewing on one side
- Bad breath
- Pawing at the mouth
- Eating soft food but leaving kibble
- Reluctance to have the head touched
Something stuck — a stick fragment, a bone shard, a grass seed — produces sudden intense licking, pawing, and distress, and warrants a same-day look.
Less common causes
- Something tasting unpleasant, including a medication just given.
- Excessive drooling from a foreign body, or from motion sickness in the car.
- Neurological causes, particularly if the licking is compulsive, rhythmic, and cannot be interrupted.
- Focal seizure activity, which can present as repetitive licking or chewing with a blank expression.
When to call a vet
- Lip licking plus vomiting, appetite loss, or lethargy
- Sudden onset with drooling and distress
- Any sign of mouth pain
- Licking that is compulsive and cannot be interrupted
- Anything alongside a swollen or painful abdomen — that combination is urgent
What to do about the stress version
Nothing to the dog. Change the situation.
Move the trigger away, give the dog room to leave, and stop whatever prompted it. Reassuring a dog that is signalling discomfort while continuing the thing causing it teaches the dog that the signal does not work — and dogs whose early signals stop working move to later ones.
This page describes what a signal can mean. Lip licking with vomiting, drooling or appetite loss is a reason to call a vet, not to watch longer.
Why the stress version is worth learning
Dogs communicate discomfort through a fairly consistent sequence, and lip licking sits near the beginning of it. Ignored often enough, a dog learns that the early signals achieve nothing and moves on to the later ones — stiffening, growling, and eventually snapping.
That is why trainers pay so much attention to it. A dog that lip licks when a child leans over it is asking for space, and giving that space keeps the early signal working. Punishing a growl teaches a dog to skip the growl; ignoring a lip lick teaches it to skip that too.
None of that requires interpreting the dog's emotions. It only requires noticing the signal and changing the situation.
Photographs and video help
Because lip licking is brief and often happens in company, it is easy to miss and hard to describe afterwards. If you are trying to work out whether a dog is uncomfortable in particular situations, a short video watched back at normal speed usually makes the pattern obvious in a way that live observation does not.
That is also the most useful thing to bring to a behaviourist or a vet, both of whom will ask what the dog was doing immediately before and after.