Canine Hypoadrenocorticism (Addison's Disease): Lifelong Management and Crisis Prevention

Addison's disease in dogs is a potentially fatal but highly manageable endocrine disorder. With appropriate mineralocorticoid and glucocorticoid replacement, affected dogs can live normal, active lives.

Key Facts

Hypoadrenocorticism (Addison's disease) is caused by destruction of the adrenal cortex, most commonly immune-mediated, leading to deficiency of both mineralocorticoids (aldosterone) and glucocorticoids (cortisol)
Addison's disease is known as the "great pretender" because its vague, waxing-and-waning signs (lethargy, weakness, vomiting, anorexia) mimic many other conditions and diagnosis is often delayed
An Addisonian crisis is a life-threatening emergency characterised by severe hyperkalaemia, hyponatraemia, hypoglycaemia, and cardiovascular collapse — requiring immediate intravenous fluid resuscitation
Diagnosis is confirmed by the ACTH stimulation test: failure of cortisol to rise in response to synthetic ACTH is diagnostic of Addison's disease
Standard treatment consists of monthly or 90-day injectable desoxycorticosterone pivalate (DOCP) for mineralocorticoid replacement and daily oral prednisolone for glucocorticoid replacement
Affected dogs require increased glucocorticoid doses ("stress dosing") during illness, injury, surgery, or stressful events to prevent crisis — owners must be educated about when and how to administer stress doses
Breeds at higher risk include Standard Poodles, Bearded Collies, Portuguese Water Dogs, and Great Danes — suggesting a genetic component to immune-mediated destruction

Welfare Considerations

Untreated or undiagnosed Addison's disease causes chronic suffering through episodic weakness, gastrointestinal distress, and the constant physiological stress of inadequate cortisol. Addisonian crises are acutely life-threatening emergencies involving cardiovascular collapse that is terrifying and rapidly fatal without treatment. However, once diagnosed and appropriately managed, dogs with Addison's disease can have an excellent quality of life indistinguishable from unaffected dogs. The welfare challenge lies primarily in diagnosis (which is often delayed), owner education about stress dosing, and ensuring compliance with regular DOCP injections. Poorly compliant management leads to recurrent welfare-significant episodes of illness.

What You Can Do

Familiarise yourself with Addison's disease signs if you own a high-risk breed, and pursue testing if episodic weakness or gastrointestinal signs occur
Carry an emergency dexamethasone injection kit when travelling with an Addisonian dog, following your vet's guidance
Ensure all family members and pet sitters understand stress dosing protocols and when to seek emergency care
Maintain regular DOCP injection schedules and monitor electrolytes as recommended by your vet
Keep an emergency contact card with your dog explaining their Addison's diagnosis for any emergency veterinary visit
Join Addison's disease dog owner support communities for peer support and management tips
Discuss long-term monitoring protocols with your vet, including frequency of electrolyte and ACTH stimulation testing