Article written by Dr Cait Hope, SASH Tuggerah Emergency Clinician Lead.
Addison’s disease is a serious but manageable health condition that affects the adrenal glands in dogs.
In this article, we’ll explain what Addison’s disease is, what causes it, the symptoms to watch out for, how it’s diagnosed and treated, and how to prevent potentially life-threatening Addisonian crises. We’ll also cover the long-term outlook for affected dogs and when to seek veterinary help.
What is Addison’s Disease in Dogs?
Addison’s disease, also known as hypoadrenocorticism, occurs when a dog’s adrenal glands fail to produce sufficient levels of essential steroid hormones — glucocorticoids (like cortisol) and mineralocorticoids (primarily aldosterone).
These hormones help regulate vital processes including electrolyte balance, stress response, blood pressure, and metabolism. Without them, a dog’s body can quickly become unbalanced, leading to serious health complications. This disease is much more common in dogs than cats.
Causes of Addison’s Disease
Several factors can lead to the development of Addison’s disease in dogs:
- Autoimmune destruction: The most common cause, where the immune system mistakenly attacks the adrenal glands.
- Genetic predisposition: Some breeds are more susceptible, including Standard Poodles, Bearded Collies, Portuguese Water Dogs, and Nova Scotia Duck Tolling Retrievers.
- Medication-related causes: Sudden withdrawal from long-term steroid use can trigger Addisonian symptoms.
- Secondary Addison’s disease: Less commonly, diseases affecting the pituitary gland or brain may disrupt adrenal hormone stimulation.
Symptoms of Addison’s Disease
Addison’s disease can present with vague signs that develop gradually or emerge suddenly in a crisis. Some people call this disease “the great pretender” as clinical disease can manifest in many ways.
Signs to look out for include:
- Vague waxing and waning signs of gastrointestinal disease
- Weakness and lethargy
- Vomiting and diarrhoea
- Loss of appetite and weight loss
- Increased thirst and urination
- Tremors or shaking
- Sudden collapse and severe life threatening hypovolaemic shock (Addisonian crisis)
How is Addison’s Disease Diagnosed?
Veterinarians use a combination of physical exams and diagnostic tests to confirm Addison’s disease:
- Physical examination: Checking for dehydration, poor condition, or signs of shock and low blood pressure.
- Blood tests: Looking for electrolyte imbalances (e.g., low sodium, high potassium) and abnormal kidney function.
- Baseline cortisol: This blood test can be run in the emergency department to help guide emergency treatment of unstable patients
- ACTH stimulation test: The gold-standard test that measures adrenal response to synthetic steroid.
- Abdominal ultrasound: May be used to assess adrenal gland size and rule out other causes.
Treatment for Addison’s Disease
In the critical setting (a patient experiencing an Addisonian crisis) treatment is aimed at treating shock and replacing fluid losses, as well as administering steroid hormonse to reverse the crisis.
Treatments include:
- Close and careful management in intensive care
- Fluid resuscitation
- Blood pressure medications in some instances
- An infusion or frequent injections of hydrocortisone or other steroid hormones.
- These patients can be extremely unwell and can require very intensive care to save their life.
Once stable lifelong management is required. Long term treatment options include:
- Hormone replacement therapy – Daily oral medications (e.g., fludrocortisone, prednisolone) or monthly injections (DOCP) to replace missing hormones.
- Crisis management – Addisonian crises require emergency treatment with IV fluids, corticosteroids, and close monitoring.
- Ongoing care – Regular checkups and blood tests to monitor hormone levels and adjust medications as needed.
Addison’s disease is treated by supplementing the body with the type of steroid that it is unable to produce by itself. This treatment needs to be continued for life and will involve either oral tablets daily or monthly injections.
Can Addison’s Disease Be Cured?
There is no cure for Addison’s disease, but with consistent treatment and monitoring, dogs can lead long, healthy lives. Medication doses may need adjustment over time based on regular blood test results.
If not well managed some patients can be triggered (by a stressful event or other illness) to go back into an Addisonian crisis. Your vet will advise how to manage medications to help avoid this.
What is the Long-Term Outlook for Dogs with Addison’s Disease?
With proper care, dogs with Addison’s disease typically enjoy a normal lifespan and good quality of life. Success depends on:
- Strict adherence to medication routines
- Regular veterinary monitoring and blood work
- Prompt attention to any changes in behaviour or appetite
How Can Addisonian Crises Be Prevented?
Preventing a life-threatening Addisonian crisis involves:
- Giving medications exactly as prescribed
- Scheduling regular vet visits for blood tests and follow-up
- Minimising stress and preparing for stressful events (e.g., travel, boarding)
- Having a crisis plan in place with your veterinarian
Avoiding a crisis in previously undiagnosed dogs can be hard as sometimes there are no signs until a crisis occurs.
Worried About Your Dog? Contact A veterinarian Today
If your dog is showing signs of Addison’s disease — such as vomiting, lethargy, or weakness — it’s important to act quickly. Early diagnosis and treatment can make all the difference. The experienced emergency team at SASH is here 24/7 to help. Don’t hesitate to call us for advice or to arrange urgent care for your dog.
