Addison's disease in dogs causes deficiency of adrenal hormones leading to life-threatening Addisonian crises and requiring lifelong hormone replacement therapy.
Dogs experiencing an Addisonian crisis face acute severe welfare compromise. The rapid deterioration from sodium loss and inability to mount a stress response causes cardiovascular collapse that can be fatal within hours without treatment. The episodic nature of Addisonian crisis means affected dogs may have multiple near-death experiences before diagnosis. Vomiting, diarrhea, muscle weakness, and profound depression characterize the crisis. With appropriate lifelong management, dogs with Addison's disease can live full, comfortable lives, but the management burden on owners is significant and poor compliance with treatment creates welfare risk. Dogs that are stressed by illness, boarding, or surgery require increased corticosteroid coverage to prevent crisis.