Comforting a frightened dog will not worsen the dog's fear. Imagine finding yourself in a situation where you are face to face with the very thing that scares you the most. Imagine that a friend reassures you that all is fine. Would your friend’s attempts at making you feel better cause you to be more afraid next time? No, b/c you cannot reinforce fear. The same is true for dogs, so go ahead and comfort your dog when she is scared.