Dog Addison's Disease: Welfare and Long-Term Management

Addison's disease (hypoadrenocorticism) is a potentially life-threatening hormonal disorder in dogs. With correct diagnosis and lifelong treatment, most dogs achieve excellent quality of life.

Key Facts

Addison's disease results from destruction of the adrenal cortex, causing deficiency of mineralocorticoids (primarily aldosterone) and glucocorticoids (primarily cortisol)
It is sometimes called "the great pretender" because clinical signs are vague and episodic: lethargy, vomiting, diarrhoea, weight loss, weakness, and shaking — often waxing and waning
It predominantly affects young to middle-aged female dogs; predisposed breeds include Standard Poodles, Portuguese Water Dogs, Nova Scotia Duck Tolling Retrievers, and Bearded Collies
Diagnosis is confirmed by an ACTH stimulation test showing absence of cortisol and aldosterone response; basal cortisol below 55 nmol/L makes Addison's unlikely and can be used as a screening tool
Addisonian crisis — acute collapse with severe electrolyte imbalance (high potassium, low sodium) causing cardiac arrhythmias — is life-threatening and requires emergency IV fluid and steroid treatment
Long-term treatment involves mineralocorticoid replacement (desoxycorticosterone pivalate (DOCP) by injection every 25–28 days, or fludrocortisone daily) and glucocorticoid replacement (prednisolone)
During periods of stress (illness, surgery, travel), glucocorticoid doses must be increased — owners must understand and implement "sick day rules"
With appropriate treatment, prognosis is excellent — most Addisonian dogs have normal life expectancy and quality of life

Welfare Considerations

Addison's disease causes significant suffering before diagnosis — dogs experience episodic illness from electrolyte imbalance and cortisol deficiency that disrupts energy metabolism, gut function, and stress response. The diagnostic journey is often prolonged because signs are nonspecific; some dogs experience multiple acute crises before the diagnosis is made. Addisonian crises are welfare emergencies involving collapse, weakness, pain, and cardiovascular instability. The welfare prognosis post-diagnosis is excellent — dogs on appropriate treatment typically become energetic, playful, and healthy. The ongoing welfare consideration is ensuring owners understand sick-day rules and carry emergency oral steroid doses to prevent crises. Monthly or 28-day injections are well-tolerated and much less stressful than daily pilling for many dogs.

What You Can Do

Know the warning signs: episodic weakness, vomiting, collapse, or shaking in young to middle-aged dogs should trigger veterinary assessment including electrolytes
If your dog has Addison's, always carry emergency oral prednisolone and know when to use it
Ensure your vet provides you with written sick-day rules for stress dosing
Wear a medical ID tag for your dog indicating Addison's disease and emergency treatment requirements
Join Addison's disease support communities — owner knowledge and vigilance is the most important factor in preventing crises