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.
- Mineralocorticoid before glucocorticoid deficiency in a dog with primary hypoadrenocorticism and hypothyroidism.
Journal of the American Animal Hospital Association · 2013 · United States
A dog was diagnosed with a rare form of Addison's disease, which is a condition where the body doesn't produce enough hormones from the adrenal glands. Initially, tests showed normal cortisol levels, but later tests revealed low levels of another hormone called aldosterone. The dog was given mineralocorticoids (hormones that help balance electrolytes) which quickly improved its
- Atypical Addison's disease in the dog: a retrospective survey of 14 cases.
Journal of the American Animal Hospital Association · 1996 · United States
This study looked at 14 dogs diagnosed with Addison's disease, a condition where the adrenal glands don't produce enough hormones. Most of these dogs were female and showed signs like eating less than usual, weakness, or vomiting. Interestingly, many had normal or slightly abnormal electrolyte levels, which are minerals in the blood that can indicate health issues. The research
- Atypical hypoadrenocorticism with intact zona glomerulosa of the adrenal cortex after long-term observation: a case report of a dog.
The Journal of veterinary medical science · 2023 · Japan
An 8-year-old male pointer was brought to the vet because he was very tired and had low levels of a protein called albumin in his blood. An ultrasound of his abdomen showed that both of his adrenal glands, which help regulate various body functions, were thinner than normal. After performing a specific test, the vet diagnosed him with atypical hypoadrenocorticism, a condition w
- Canine hypoadrenocorticism: pathogenesis, diagnosis, and treatment.
Topics in companion animal medicine · 2014 · United States
Hypoadrenocorticism, also known as Addison disease, is a rare condition in dogs that happens when the adrenal glands are damaged by the immune system, leading to lower levels of important hormones. Dogs with this condition may show symptoms like upset stomach, weakness, weight loss, and low blood volume. While some dogs may have normal electrolyte levels, common lab findings in
- Corticosterone- and aldosterone-secreting adrenocortical tumor in a dog.
Journal of the American Veterinary Medical Association · 2005 · United States
A dog was taken to the vet because it showed signs of having too much cortisol in its system, which can happen with certain adrenal gland tumors. Blood tests showed high sodium and low potassium levels, and a special injection didn't raise the cortisol levels as expected. Imaging tests revealed a tumor on the adrenal gland, which was confirmed to be an adrenocortical carcinoma
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.