Addison's Disease

Addison’s disease, also known as hypoadrenocorticism, is a condition where the adrenal gland does not produce adequate levels of hormones needed to balance metabolic functions. The adrenal gland produces two types of hormones:

Corticosteroids are hormones that allow us to handle stress, the “flight or flight syndrome”. They control protein and glucose metabolism which are the main sources of energy that allow us to cope with stress factors.
Mineralocorticoids are hormones that control electrolyte balance. This in turn affects kidney function.

The cause of Addison’s disease is rarely found, but it typically affects younger patients, typically 4-5 years of age and it affects females twice as often as males. This disease affects dogs, and very rarely, cats.  Clinical signs can range from no signs, to an acute crisis where the patient is presented comatose.  The first signs an owner might notice is a dog that is consuming more water  and urinating more. As the disease progresses, lethargy, inappetance, vomiting and cardiac signs develop as the potassium levels rise.

Diagnosis is made based on clinical signs, urinalysis, and bloodwork. The classic Addisonian has an elevated potassium and a decreased sodium. The ratio of sodium to potassium typically drops below 25. Kidney values will begin to elevate as the disease progresses. Not all Addisonian patients fit this classic presentation and the clinician must be open to the possibility of Addisosn’s disease in a young dog that presents with unexplained signs of kidney disease even with normal electrolyte levels. Confirmation of the disease is made with a blood test called an ACTH Stimulation test. ACTH (adreno corticotropic hormone) is a hormone produced in the pituitary gland in the brain that stimulates the adrenal gland to secrete corticosteroids and mineralocorticoid hormones. Addisonian patients have low corticosteroid levels and do not stimulate post acth administration.

Treatment is usually very successful. A patient in crisis is given intravenous fluids with sodium chloride, and corticosteroids. Mineralocoricoid supplementation is begun and can be accomplished with an oral medication called Florinef,  or an every 28 day injection called Percortin. Dogs tend to do better with the injection. Care must be taken with future stresses such as surgery, and low dose oral steroid supplementation may be needed for life.

Dogs can live normal happy, productive lives with Addison’s disease as long as they are managed appropriately. The most famous human that had Addison’s  disease was President John F. Kennedy.