Please analyze the tweet "“The #greatest fear #dogs know is the #fear that you will not come back when you go out the #door #without them.”   \n  ―#Stanley #Coren" and classify its emotional content. Choose from the following emotions: anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust. If no emotions are detected, respond with "neutral or no emotion".
fear