This question was forwarded to me related to the webinar on New Research Insights Into Canine Addison's Disease ...
Can a dog who has been diagnosed with Addison's someday not be an Addisonian?
No, unless the Addison's disease is "iatrogenic," meaning caused by medical treatment. If the diagnosis of spontaneous hypoadrenocorticism is correct, the dog will never be cured of the disease but can lead a very normal life with medical therapy.