Dream about big green dog stands for your concerns about how others perceive you. You are feeling tremendous mental strain and are trying to reach out for help. You are being overly indulgent and living a life of excess. Your dream is about your excitement about a new relationship. You need to acknowledge some feelings and deal with them.
Big green dog dream is sometimes your desires for more emotional freedom/expression and self power. You may be on a self-destructive and self-defeating path. You need to show restraint and control. This points at a new opportunity or challenge. You need to keep your guard up.
If you dreamt about big green dog:
Don't try to hide the truth. Your tendency is to bend the facts in order to protect yourself and others. Don't. Doing so will only cause even greater harm down the road. Be sure to disclose all facts at this time. Honesty is a key theme for you.