Addison's Disease (Hypoadrenocorticism)

Condition Overview

The adrenal glands, found in the abdomen above the kidneys, are important in the production of corticosteroids and other hormones that regulate body functions.

Symptoms

The signs of Addison's disease are lethargy, muscle weakness, intermittent vomiting and diarrhea, and slow pulse.

All symptoms +

Causes

Addison's disease is caused by inadequate production of corticosteroids and mineralocorticoids.

In some cases, this uncommon condition arises after other illnesses, including infections, tumors, and toxic drugs, destroy the adrenal glands. An autoimmune reaction, in which the antibodies are directed against the cells of the adrenal cortex (the part of the adrenal gland that produces corticosteroids), may be responsible for cases in which the cause in unknown. There may be a genetic predisposition in Bearded Collies, Portuguese Water Dogs, and Standard Poodles.

An iatrogenic form of Addison's disease occurs after corticosteroids are administered to treat a medical condition. The corticosteroids have the side effect of putting the adrenal glands at rest. An abrupt withdrawl of the drug can produce a temporary deficit of hydrocortisone and cause an acute Addisonian crisis with shock and circulatory collapse. Another common iatrogenic cause of Addison's disease is the use of mitotane to treat Cushing's syndrome.

Diagnosis

This disease should be considered when a dog unaccountably collapses. The diagnosis is made by an ACTH stimulation test. In a positive test, the adrenal cortex does not respond to an injection of ACTH by increasing the concentration of cortisol in the serum.

Treatment

Shock associated with acute adrenal insufficiency responds rapidly to corticosteroids and intravenous fluids. Chronic adrenal insufficiency can be controlled by giving an oral cortisone preparation such as prednisone daily, along with fludrocortisone acetate for mineralocorticoid replacement. Treatment is life-long. The dosage varies with the severity of the disease and must be determined by your veterinarian.

Prevention

There is no known prevention for this condition.

Support

Please contact your veterinarian if you think your pet may have this condition.