[dottiesyrky]

Have you tried the product called DAP that contains dog appeasing pheromones that lactating female dogs emit to calm the pups? This pheromone is also said to have the same affect in adult dogs. It comes in a diffuser (like Glade) that plugs in the power outlet, a spray and a collar. I have used it and it does appear to calm my dog when he is anxious or I am going to leave him alone.
However, you would have to try it for your dog to see if it works for him.
My dog really was affected by a thunderstorm and ever since he reacts to almost any noise, particularly aircraft. I try to remain calm and pretend it is nothing and talk quietly and that seems to calm him.
It does not take much for dogs to remember bad things!
Good Luck!