If you’re slapped by another human you probably take offense… it’s a pretty clear sign that the person is deeply upset by something you’ve done. But a slap from a dog isn’t an indication that the pooch is angry with you. In fact, a slap can be a sign of affection or just an attempt to get your attention.
A dog slapping another dog is showing that it trusts the other pooch. It’s almost the way we’d pat each other on the back – a friendly or congratulatory move.