Dogs are able to communicate their joy and contentment through a number of different means, including their body language as well as their behavior.
Some dogs may insist on bringing their favorite toy to you, while other dogs
will become very thrilled if they are served their favorite snack,
and yet others will sit by the door for hours waiting for their favorite people to come home.
According to the video, the five signs include the following: the dog rolling over onto its back and exposing its belly to you
a dog initiating contact with humans such as rubbing against you or butting its head against you
the dog getting the zoomies (and the video states that researchers say only happy and healthy dogs get the zoomies);
the dog sleeping (because healthy dogs sleep for up to 16 hours a day); and the dog having "soft eyes," which are eyes that are relaxed and gentle.