DOGS · Condition guide
Addison's disease in dogs: the great pretender, in real cases
Addison's disease is the mirror image of Cushing's: the adrenal glands don't make enough cortisol (and usually not enough aldosterone either). Because cortisol does so many things in the body, the signs are vague and varied — vomiting, diarrhea, lethargy, weight loss, intermittent weakness. The picture often waxes and wanes, which is why it's nicknamed the "great pretender".
Untreated Addison's can crash dramatically into an "Addisonian crisis": shock, collapse, low blood sugar, dangerous potassium spikes. But once diagnosed, lifelong replacement therapy works very well and most dogs live a normal lifespan.
What vets typically check for
- Baseline CBC + chemistry + electrolytes (classic finding: Na:K ratio < 27).
- Lack of a stress leukogram in a sick dog is a key clue — points clinicians toward Addison's.
- Confirmatory: ACTH-stimulation test. A flat-line cortisol response is diagnostic.
- In "atypical" Addison's, electrolytes look normal — only the ACTH-stim confirms it. Easy to miss.
- Treatment: daily prednisone + monthly DOCP injection (or daily fludrocortisone).
Not a replacement for veterinary care. Use this to walk into the conversation prepared, not to self-diagnose.
Real cases from the veterinary literature
Peer-reviewed reports our semantic search surfaces for Addison's disease (hypoadrenocorticism). Click into any case for the full abstract — or run a personalised search with your pet's exact details.
- Vena Caval Hematoma Secondary to Adrenal Hemorrhage From an Addisonian Crisis in a Dog.
Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association · 2026 · United States
An 11-year-old spayed female American Staffordshire Terrier was brought in for an Addisonian crisis, which is a serious condition caused by insufficient hormone production from the adrenal glands. An abdominal CT scan showed a mass on the right adrenal gland that was affecting the vena cava, a major vein. The dog was treated for the crisis, but the owners chose not to pursue fu
- Frequency of abnormal C-reactive protein concentrations in blood of dogs with hypoadrenocorticism.
Journal of veterinary internal medicine · 2026 · Australia
A group of 51 dogs with Addison's disease (hypoadrenocorticism) had their blood tested for C-reactive protein (CRP), a marker that can indicate inflammation. The results showed that 75% of these dogs had high CRP levels, even if they didn't have any other known inflammatory issues. This suggests that if your dog has vague symptoms and high CRP levels, Addison's disease could be
- Pharmacokinetics and pharmacodynamics of desoxycorticosterone pivalate in dogs with hypoadrenocorticism.
Journal of veterinary internal medicine · 2026 · United States
A group of 21 dogs with newly diagnosed hypoadrenocorticism (HA), a condition where the body doesn't produce enough hormones, were treated with desoxycorticosterone pivalate (DOCP) to help manage their symptoms. The dogs received either a low dose or a standard dose of the medication, and researchers measured how well the drug worked over time. Both doses were effective, but th
- A variant in RESF1 is associated with Addison's disease and multiple autoimmune syndrome in young Nova Scotia Duck Tolling Retrievers.
Scientific reports · 2026 · United States
A young Nova Scotia Duck Tolling Retriever was diagnosed with Addison's disease, which means its body wasn't producing enough important hormones. This condition is rare in dogs but seems to be more common in this breed, especially in younger dogs. In a study of 24 affected dogs, many also had other autoimmune issues, leading to a significantly shorter lifespan, averaging just 2
- Asymmetric Multifocal Neurological Signs in a Dog With Eunatremic, Eukalemic Hypoadrenocorticism With Severe Hypoglycemia.
Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001) · 2025 · Australia
A 7-year-old neutered male miniature Poodle was brought to the vet after collapsing, vomiting, and showing unusual neurological signs like a head tilt. The dog was in shock and had low blood sugar, but tests showed no issues with the brain structure. After treatment with glucose and a steroid called dexamethasone, the dog's condition improved slowly over a couple of days. By th
- Efficacy and side effects of long-term treatment strategies of canine primary hypoadrenocorticism.
Frontiers in veterinary science · 2025 · Germany
A group of 244 dogs with primary adrenal insufficiency (hypoadrenocorticism) were treated with different medication combinations to see which worked best. The treatments included a mix of prednisolone with either desoxycorticosterone pivalate (Zycortal or Percorten-V) or fludrocortisone. All treatment options helped restore normal activity and quality of life for the dogs, and
Frequently asked questions
- Why is Addison's called "the great pretender"?
- Because it presents as recurrent GI issues, intermittent lethargy, or vague "off" behaviour — symptoms that look like many other things. Many dogs are misdiagnosed with chronic GI disease or food sensitivity for months before someone runs the ACTH-stim.
- What's an Addisonian crisis?
- It's an acute, life-threatening lack of cortisol and aldosterone — the dog collapses, has bradycardia, severe hyperkalemia, and shock. It's a true emergency. Aggressive IV fluids, dextrose, and IV steroids reverse it within hours when caught.
- Is Addison's hereditary?
- There's strong breed predisposition — Standard Poodles, Bearded Collies, Portuguese Water Dogs, Nova Scotia Duck Tolling Retrievers, and Leonbergers all carry elevated risk. The exact genetics are still being mapped, but a family history significantly raises suspicion.