Addison’s Disease in Dogs: Vague Illness, Collapse Risk, and Why Testing Matters
Waxing-and-waning lethargy, vomiting, and shaking can hide Addison’s disease—until a stressful event triggers a life-threatening crisis.
Intermittent vomiting and lethargy are symptoms, not a diagnosis. Addison’s disease (hypoadrenocorticism) occurs when the adrenal glands do not produce enough corticosteroid and, in typical cases, mineralocorticoid hormones. Dogs may seem vaguely unwell for weeks — poor appetite, shaking, diarrhoea — then crash into an Addisonian crisis with collapse, low heart rate, and severe electrolyte imbalance. Stress can precipitate crisis. Vague waxing-and-waning illness should never simply be dismissed as “sensitive stomach” without appropriate testing when the pattern fits.
This article is educational and does not replace a hands-on veterinary examination. If your dog collapses, has severe vomiting and diarrhoea, weak pulse, or extreme lethargy, seek emergency care.
On This Page
- What Addison’s looks like
- Why it happens
- Addison’s vs. other vague illnesses
- Chronic signs vs. crisis
- When it’s an emergency
- What a vet will check
- How it’s treated
- Living with Addison’s
- Outlook
- Before your appointment
- FAQ
What Does Addison’s Disease Look Like?
- Waxing and waning lethargy
- Intermittent vomiting or diarrhoea
- Shaking or muscle weakness
- Increased thirst in some dogs
- Weight loss
- Collapse during stress (boarding, illness, hard exercise)
- Slow heart rate and weak pulses in crisis
- Dehydration
Why Does Addison’s Happen?
Most cases are immune-mediated destruction of adrenal tissue. Certain breeds appear over-represented in clinical reports. Without enough cortisol and aldosterone, dogs cannot maintain blood pressure, electrolytes, and stress responses normally.
Addison’s vs. Other Causes of Vague Illness
| Feature | May suggest Addison’s | May suggest GI or other disease |
|---|---|---|
| Pattern | Often intermittent, stress-related flares | May follow diet change or toxin |
| Electrolytes | Classic sodium/potassium changes in many cases | Variable |
| Confirming test | ACTH stimulation test (as interpreted by vet) | Depends on suspected system |
When Is It an Emergency?
- Collapse or extreme weakness
- Severe vomiting/diarrhoea with dehydration
- Bradycardia with poor pulses
- Suspected crisis after stress in a known Addisonian dog
Managing a newly diagnosed Addisonian dog?
Our Healthcare Consultations pathway helps you organise medication scheduling and stress-planning questions for your veterinary team.
What Will a Veterinarian Check?
History, electrolytes, kidney values, ECG when indicated, and ACTH stimulation testing to support the diagnosis. Crisis dogs need stabilisation first.
How Is Addison’s Treated?
Hormone replacement — glucocorticoid and, for most typical cases, mineralocorticoid support — is lifelong. Doses and products are selected by the veterinarian. Crisis treatment is hospital-based. Never adjust doses from internet charts.
Living With Addison’s
- Give medications exactly as prescribed
- Discuss stress-dose plans with your vet before boarding or surgery
- Keep emergency clinic contacts available
- Attend electrolyte monitoring visits
Can It Get Better?
Addison’s is manageable for many dogs with consistent replacement therapy. Untreated crisis can be fatal. Quality of life is often excellent once stable.
FAQ
Is Addison’s the opposite of Cushing’s?
They involve adrenal hormones in different directions; testing and treatment differ completely.
Can a dog outgrow it?
Typical primary Addison’s requires lifelong management.
Conclusion
Vague intermittent illness plus stress-related collapse should raise Addison’s as a differential. Testing and replacement therapy save lives.
Medical disclaimer: Educational content only.
Educational content only. This page does not diagnose disease or replace care from a licensed veterinarian. Seek in-person help for emergencies or worsening symptoms.