Just a note that we found a great new source of Percortin, and you should too, if you're living with an Addison's dog.
http://www.petrescuerx.com/index.cfm/product/312_133/percorten-v.cfm

PetRescueRx is a not-for-profit company that donates it's profit to rescue organizations, of which Addisons Dogs is one.  The price on Percortin is about the same as PetMeds after you go through all the price matching, coupons, etc.  The service is prompt.  It's still expensive, but you feel a little better about where the profitability is going.
Jack in his "Go Giants" bandana...