This doesn't mean a dog can diagnose a disease simply by sniffing someone. However, unusual interest may occasionally be linked to scent changes that the animal finds different or noteworthy.
When Is the Behavior Normal?
In most cases, sniffing is completely normal canine behavior. Dogs are naturally curious and gather information through scent exploration.
Puppies and younger dogs are especially likely to investigate unfamiliar people this way because they are still learning social boundaries.
The behavior is generally harmless unless it becomes excessive or difficult to control.
How to Politely Stop It
If your dog tends to make guests uncomfortable, the best approach is gentle redirection.
Some helpful strategies include: