Addison’s disease (hypoadrenocorticism) is a condition where a dog’s adrenal glands, two small hormone-making glands, stop producing the steroid hormones cortisol and aldosterone, as the PDSA explains. It can affect any dog, and the early signs are so vague that it is easy to miss. Once your vet has confirmed it, it can be managed for life, so if something seems “off” with your dog, speak to your vet.
At a glance
- What it is: the adrenal glands stop making two key steroid hormones.
- Who it affects: any dog, though the PDSA says it is most common in middle-aged females and seen more often in some breeds.
- Urgency: contact your vet if signs appear, especially if they keep coming back; an Addisonian crisis (such as collapse) is an emergency.
- Vet needed? Yes. Only a vet can diagnose and treat it.
Signs to look for
The PDSA says early signs are vague and can come and go: low energy, a reduced appetite, weight loss, occasional vomiting or diarrhoea, and drinking and urinating more than usual. Some dogs are weak or wobbly, or simply not “quite right”. Cornell’s vet college nicknames Addison’s “the great pretender” because it mimics other diseases.
The serious version is called an Addisonian crisis (a sudden, severe flare-up). The PDSA lists collapse, a slow heart rate and coma, and warns that it can be fatal if left untreated. Because so many of these signs overlap with vomiting and diarrhoea, our guide to sick dog symptoms can help you decide how fast to call.
Causes and risk factors
The PDSA says that in most cases the immune system attacks the adrenal glands, which makes it an immune-mediated condition. It is the opposite of Cushing’s disease, where the body makes too much steroid.
According to the PDSA it is most common in middle-aged (4 to 6 year old) females, and the breeds it lists as seen most often are Standard Poodles, West Highland White Terriers, Great Danes and St Bernards. A Royal Veterinary College (RVC) research information sheet also names Standard Poodles and Bearded Collies as more susceptible, while stressing that any breed can be affected. The two sources do not match exactly, which tells you that breed lists are a guide, not a rule.
When to call your vet
Speak to your vet if your dog shows these signs, particularly if they keep returning. The PDSA is clear that a dog showing signs of an Addisonian crisis is an emergency, so contact your vet urgently. If you do not have a regular practice, our guide to finding the best vets near you is a good place to start. If your dog is eating less but otherwise bright, our piece on how to tell if your dog isn’t eating enough may help you describe it to the vet.
- 1. Notice
Low energy, reduced appetite, or drinking more than usual - 2. Speak to your vet
Contact your vet if signs appear; a crisis such as collapse is an emergency - 3. Vet examines
Blood and urine tests, and possibly an ECG or ultrasound - 4. Options
Treatment options your vet may discuss: lifelong hormone replacement - 5. Ongoing care
Regular check-ups with repeat blood tests now and then
How vets diagnose it
The PDSA says vets may run blood and urine tests, and possibly an ECG (a heart trace) and an ultrasound scan. Cornell adds that blood and urine tests can show imbalances in sodium and potassium, and that an ACTH stimulation test confirms it by measuring cortisol before and after an injection of a synthetic hormone. X-rays or ultrasound may be used to rule out other causes. Which tests your dog needs is your vet’s call.
What vets generally do about it
The PDSA says dogs usually need medication for the rest of their lives: a monthly injection given by the vet to replace aldosterone, plus daily steroid tablets at home to replace cortisol. If a dog is in crisis, treatment is emergency care with a fluid drip and intravenous steroids, and long-term treatment starts once the dog is stable. The exact plan and doses are decided by your vet.
Living with it and prevention
The PDSA says dogs need regular check-ups, at least monthly, with repeat blood tests now and then. Steroids help the body cope with stress, so vets may advise changing the dose around stressful events such as fireworks or a house move. Never change your dog’s medication without speaking to your vet first.
The PDSA describes the outlook as good for most dogs, who can live a relatively normal life, though it is poorer if treatment does not work, another condition such as diabetes is present, or a crisis goes untreated. Lifelong treatment can be costly, and the PDSA suggests considering insurance early. Our UK pet insurance guide is a starting point. None of the sources we used says Addison’s can be prevented.
Related conditions
- Cushing’s disease in dogs, the opposite problem, with too much steroid
- Diabetes in dogs, which the PDSA says can complicate Addison’s
- Kidney disease in dogs, another cause of drinking and weight changes
- Vomiting in dogs and diarrhoea in dogs
- Back to the dog illnesses A to Z
Specialist help
The Kennel Club has a DNA risk test for Juvenile Addison’s disease (JADD). It estimates risk rather than giving a diagnosis, and says affected puppies usually show signs around 5 months old. It is mainly of interest to breeders and anyone buying a puppy from a breed where it applies, so ask the Kennel Club or your vet whether it is relevant.
Sources
- PDSA: Addison’s disease in dogs
- Cornell University College of Veterinary Medicine: Addison’s disease in dogs
- Royal Veterinary College: Addison’s disease study information sheet
- The Kennel Club: Risk test, Juvenile Addison’s disease
Frequently Asked Questions
What is Addison’s disease in dogs?
It is a condition where the adrenal glands stop producing the steroid hormones cortisol and aldosterone, most often because the immune system attacks them. Only a vet can diagnose it, so speak to your vet if you are worried.
Can a dog with Addison’s disease live a normal life?
The PDSA says most dogs have a good outlook and can live a relatively normal life with lifelong medication and regular check-ups. Your vet will advise on the plan for your dog.
What is an Addisonian crisis?
It is a sudden, severe flare-up of Addison’s disease. The PDSA lists collapse, a slow heart rate and coma, and calls it an emergency, so contact your vet urgently.
Can I change my dog’s Addison’s medication myself?
No. The PDSA says never to adjust your dog’s medication without speaking to your vet first, even around stressful events when a vet may advise a change.
This page is general information, not veterinary advice. If you are worried about your dog, speak to your vet. Written by Georgiana & Figo, who are dog owners, not vets. Have a look around Calmshops for everyday dog essentials.
