Addison's disease (hypoadrenocorticism) in dogs

What is Addison's disease?

Addison's disease (hypoadrenocorticism) occurs when the immune system attacks and destroys the outer layer of the adrenal glands. As a result, the adrenal glands produce insufficient mineralocorticoids (which regulate sodium and potassium) and glucocorticoids (which manage stress and suppress inflammation) [1][3].

Approximately 64–70% of affected dogs are female, and the average age at diagnosis is four years [1]. Breeds with an increased risk include the Nova Scotia Duck Tolling Retriever, Standard Poodle, Portuguese Water Dog and Bearded Collie [3].

Atypical form

Some dogs have only a glucocorticoid deficiency with normal electrolytes. This is called the atypical or secondary form and is often recognised later because electrolyte abnormalities are absent [1][4].

Diagnosis

Diagnosis requires an ACTH stimulation test: a cortisol value after ACTH injection below 2 µg/dL (55 nmol/L) confirms the condition [3]. Blood tests often show a low sodium/potassium ratio, anaemia and low blood sugar.

The Addisonian crisis: immediate danger

When hormone deficiencies acutely worsen — due to illness, stress or if the condition is still unknown — an Addisonian crisis can occur. This is a life-threatening emergency: potassium rises to dangerous levels, the heart rhythm becomes disturbed and blood pressure plummets [2]. Immediate intensive treatment with intravenous fluids, parenteral glucocorticoids and heart rhythm monitoring is then essential [2].

Treatment: lifelong hormone therapy

With adequate treatment, the prognosis is excellent — the median survival time after diagnosis exceeds 4.7 years and death is rarely related to the disease itself [1].

Standard treatment consists of two pillars:

During illness, surgery or other stressful situations, the prednisone dose must be temporarily increased. This is called stress dosing and must always be discussed with the veterinary surgeon beforehand [1][4].

Natural and supplementary options: an honest assessment

There are no herbs, dietary supplements or alternative treatments proven to replace adrenal function or make hormone therapy unnecessary [1][3][4]. In a dog with Addison's disease that is untreated or inadequately treated, the outcome is fatal.

Some points that are occasionally raised:

• Adaptogenic herbs (e.g. ashwagandha, liquorice): No clinical evidence in dogs with hypoadrenocorticism; liquorice extract can further disrupt electrolyte balance and interactions with corticosteroids have been reported.
• Dietary adjustments: A balanced, low-stress diet supports general well-being but has no effect on hormone regulation.
• Acupuncture or homeopathy: No evidence of efficacy for this specific condition.

It is not safe to experiment with reducing or omitting medication based on supplementary agents. Any dose change must always be made in consultation with the treating veterinary surgeon [4].

Monitoring

Regular checks are essential: electrolytes, kidney function and cortisol are measured periodically to adjust the dose. Owners learn to recognise early signs of an impending crisis so that rapid intervention can occur [1][2].