food traces
lotions
scents
Dogs have an extremely sensitive sense of smell and taste. Sometimes they lick simply because your skin tastes interesting.
It May Be a Stress Signal
Some dogs lick excessively when nervous.
If licking happens alongside:
yawning
avoiding eye contact
tucked tail
lip licking
pacing
it may signal anxiety rather than affection.
What Studies Show
Research into canine social behavior suggests licking can play multiple roles beyond affection.
A study published in Applied Animal Behaviour Science has noted that dogs use licking as part of social communication