Thank you for helping this very giving military dog who has likely served us all well. Continental has a good program for shipping pets and both Delta and Northwest have pet transport as well. On our home page, www.pilotsnpaws.org
, one of our commercial pilots, Sarah Murphy Case has written a very informative article and guidelines about how to use commercial transport. I would suggest reading that and seeing if you can find a direct flight for this pup. Even if volunteers have to drive a ways on either end I would definitely look for a direct flight. It is also possible to fly with him and check him as part of your baggage. There is a fee, of course, but this way someone would be on board to monitor his status along the way.
These longer distances are difficult but not impossible for volunteer PNP pilots. You may be able to find volunteer pilots by breaking the route into 300 mile legs with a temp foster set up at each destination point. I hope this all works out for what I am sure is a wonderful dog.