Dogs wag their tails when they are happy, excited, or content. This is often accompanied by other behaviors, such as panting, licking, and wagging their whole body.
Dogs wag their tails when they are excited, such as when they see their owner coming home or when they are about to go for a walk.
Dogs wag their tails when they are afraid, but this is often a more subtle wag. The tail may be held low and wagged quickly.
Dogs wag their tails when they are trying to assert dominance. This is often accompanied by other behaviors, such as standing tall and staring.
Dogs also wag their tails to communicate with other dogs. The speed and direction of the wag can indicate different things, such as playfulness, aggression, or submission.
There are other reasons why dogs wag their tails, such as to cool themselves down, to attract attention, or to relieve pain.
The best way to understand your dog's tail wags is to observe them in different situations. Pay attention to the speed, direction, and other behaviors that accompany the wag.