Dogs usually feel better within days of starting treatment

"Dogs usually feel better within days of starting treatment, and most symptoms are gone within two to four weeks. The main challenges to life-long treatment are its expense and the effort involved in monitoring electrolyte levels, administering medication, and keeping a close eye on the patient for signs of problems."

 

https://www.whole-dog-journal.com/health/addisons-disease-in-dogs-detection-and-treatment/