When my dog, Ali, and I play fetch I sometimes feel it’s reaffirming a contract of trust between the two of us.
Me: I as your human promise to hold and throw the ball for you through rain and shine for as long as my arm is attached to my body.
My dog: I give you my ball as a symbol of my trust and I promise to come back to you even if I am completely off leash. Now please throw the ball or forever ..no just please throw the ball.
So in the end my dog trusts me enough to let me have her ball and I trust her enough to come back after I throw it.