Addison's Disease in Dogs: Symptoms and UK Treatment Costs
Addison's disease (hypoadrenocorticism) is caused by insufficient production of cortisol and aldosterone from the adrenal glands. It is sometimes called 'the great pretender' because its symptoms — vomiting, lethargy, weakness — mimic so many other conditions. An Addisonian crisis, where cortisol crashes suddenly, can be fatal without immediate treatment.
Key takeaways
- Addison's disease is called 'the great pretender' because its symptoms mimic many other conditions — diagnosis requires a specific ACTH stimulation test.
- An Addisonian crisis is a life-threatening emergency: a suddenly collapsed, weak dog with vomiting needs immediate veterinary care.
- With proper management, dogs with Addison's disease live a fully normal life — but treatment is lifelong.
What Is Addison's Disease?
The adrenal glands, located near the kidneys, produce two vital hormones: cortisol (which helps the body respond to stress and regulates metabolism) and aldosterone (which controls sodium, potassium and water balance). In Addison's disease, the adrenal glands fail — most commonly because the immune system attacks the adrenal cortex (primary hypoadrenocorticism). Rarely, the problem lies in the pituitary gland failing to signal the adrenals properly (secondary hypoadrenocorticism).
The condition is more common in young to middle-aged female dogs. Breeds with notably higher risk include Standard Poodles, Bearded Collies, Portuguese Water Dogs, Nova Scotia Duck Tolling Retrievers and West Highland White Terriers. It can occasionally be caused by abrupt withdrawal of long-term steroid medication, which suppresses the adrenal glands.
Symptoms and Addisonian Crisis
The chronic, low-grade symptoms of Addison's disease include intermittent vomiting, diarrhoea, lethargy, weight loss, shaking episodes and reduced appetite — often waxing and waning, which is one reason the diagnosis is frequently missed or delayed. Dogs may improve with supportive care only to relapse a few weeks later.
An acute Addisonian crisis is triggered by a significant stressor (illness, injury, changes in routine) and is life-threatening. The dog collapses, becomes profoundly weak, suffers severe vomiting and diarrhoea, goes into hypovolaemic shock (very low blood pressure and weak pulse) and may become unresponsive. The classic blood test finding is a reversed sodium:potassium ratio. This is a genuine emergency — without immediate IV fluids and corticosteroids, the dog will die. Any dog with unexplained collapse must be seen by a vet urgently.
Diagnosis
Diagnosis is made via the ACTH stimulation test, which is the definitive test for Addison's disease. It measures cortisol before and after injection of synthetic ACTH — in Addisonian dogs, the adrenal glands cannot respond and cortisol remains low. This test costs approximately £80–£150. Routine biochemistry will often show a characteristic electrolyte abnormality (low sodium and high potassium), which is a strong pointer towards the diagnosis.
Total diagnostic costs including the initial consultation, blood panel and stimulation test typically range from £200–£400. In a crisis, emergency stabilisation costs — IV fluids, injectable medications, hospitalisation — can reach £500–£1,500 before the underlying diagnosis is even confirmed. Misdiagnosis is unfortunately common; the PDSA notes that the average time from first symptoms to Addison's diagnosis can be months.
Treatment and Long-Term Management
Once diagnosed, Addison's disease is managed for life. The standard approach combines oral fludrocortisone (to replace aldosterone) or monthly desoxycorticosterone pivalate (DOCP) injections with daily oral prednisolone (to replace cortisol). DOCP (Zycortal) injections cost approximately £50–£100 per month, and additional prednisolone is relatively inexpensive. Dogs on fludrocortisone alone require regular electrolyte monitoring every one to three months.
During times of stress (illness, surgery, boarding), the steroid dose must be temporarily increased — owners are taught to do this as part of managing the condition. Most dogs with Addison's disease that are well managed live a completely normal life expectancy. This is one of the most rewarding diagnoses in veterinary medicine because once the correct treatment is in place, the transformation can be remarkable. Lifetime pet insurance is highly recommended given the ongoing nature of treatment.
Find a Vet Near You
Addison's disease requires lifelong monitoring and medication. Use CompareMyVet at app.comparemyvet.uk to compare prices at local practices and find a vet who can provide ongoing management at a fair and transparent cost.
Related guides
Common questions
Monthly medication costs are typically £50–£120 depending on which protocol your vet uses. Add three to four blood monitoring tests per year at £50–£100 each, and annual costs are broadly £800–£1,500. An emergency Addisonian crisis can cost £500–£1,500 on top of ongoing management.
There is a clear genetic component in certain breeds, particularly Standard Poodles, Bearded Collies and Nova Scotia Duck Tolling Retrievers. Responsible breeders are increasingly aware of this, and some breed health schemes are tracking incidence. Dogs diagnosed should not be used for breeding.
Yes, absolutely. Provided medication is given consistently and doses are adjusted during stress events, most dogs with Addison's disease live a completely normal lifespan with excellent quality of life. Owners describe the transformation after correct diagnosis and treatment as life-changing.
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