sorry to disagree a little with the last post but my understanding of canine phobia issues is as follows. Don't make a huge fuss about your dog being scared - by acknowledging it and saying 'There, there - poor dog' etc you are only confirming his suspicions that there is something to be scared of and you are concerned too.-This only adds to his fears - you should just act in a normal unfluster way. Obviously allow the dog a dark quiet corner that he feels safe in but ignore him. There has been lots of success with conditioning therapy - get a tape recording of a thunderstorm and begin by playing it very, very softly as often as is practical - the longer the better - gradually increase the volume as the dog's sensitivity to it decreases. Eventually he should accept the recording at quite a high level - when this happens keep playing the tape at odd intervals and certainly if there is a storm due. Hope this helps.