Do you mean like after a walk, or when you get home>? When my dog does that its cause he is too excited I rub his neck under his chin to calm him down. If its really bad maybe take to vet cause he might not be able to breath properly

If its a regular size 200g dip/salsa id say 1 per 10 people, but not everone will eat dip if you are going to have a lot of other snacks I would use less