Is Addison's disease common in Poodles?

It is best documented in the Standard Poodle. In one survey, 8.6 per cent of Standard Poodles were affected, and heritability in that size has been estimated as high, around 0.76 (Famula et al., 2003; Friedenberg et al., 2016). No separate figures exist for Miniature or Toy Poodles, but the Poodle appears on breed-risk lists for the disease, so owners of every size should know the signs.

What are the first signs of Addison's disease in a dog?

The signs are vague and tend to come and go: poor appetite, vomiting, diarrhoea, lethargy, weight loss, weakness or trembling, and sometimes drinking and urinating more. Stress often makes them worse. If episodes like this keep returning, ask your vet whether Addison's has been ruled out.

Can a dog with Addison's live a normal life?

Yes. With a correct diagnosis, lifelong medication and regular blood checks, specialists describe the outlook as excellent, with a normal quality and length of life. The medication must never simply stop, and the dose needs adjusting with your vet around stress or illness.

Is there a DNA test for Addison's disease in Poodles?

Not a validated one. Researchers have been looking for the genes involved for years, but breeders have no reliable DNA test to screen parent dogs. A good breeder is open about disease in the family lines instead.

Addison's Disease in Poodles: Signs, Testing and Treatment

By The Poodle Guide editorial team · Updated on October 12, 2026

Close-up of an apricot-coloured curly Poodle lying on a grey carpet with its head down, looking up calmly

Your Poodle eats badly for a few days, vomits once and seems flat. Then he perks up again. A few weeks later it happens again, with no clear cause. Vague, recurring signs like these can mean many things, and occasionally they mean Addison's disease. Vets nicknamed it "the great pretender" because it imitates so many other illnesses. This guide explains what Addison's is, which signs to take seriously, how it is diagnosed and why most dogs go on to live well with it.

What is Addison's disease?

Addison's disease, known medically as hypoadrenocorticism, means the adrenal glands produce too little of the hormones the body relies on. Two matter most:

Cortisol helps the body cope with stress and supports digestion and blood sugar.
Aldosterone controls the balance of salt and potassium, and through it blood pressure and heart rate.

In most affected dogs the adrenal glands fall short on both. An immune-mediated process is the suspected cause in many cases, but the exact trigger is not known.

Poodles and Addison's: what do we actually know?

The Poodle is regularly listed among the breeds at higher risk, and the research is concentrated on the Standard Poodle. In one survey, 8.6 per cent of Standard Poodles had the disease, and heritability was estimated at about 0.76, which is high (Famula et al., 2003; Friedenberg et al., 2016). For Miniature, Medium and Toy Poodles there are no separate figures. Because "the Poodle" appears in breed-risk lists without a size attached, we would not tell you a Toy is safe, and we would not tell you it is at the same risk as a Standard either. We simply do not know. If you are unsure which size you have or are choosing between them, our guide to Poodle sizes covers the differences.

A few more patterns are worth knowing:

The median age at diagnosis is around 4 years, although cases range from 2 months to 14 years.
Many studies find that 60 to 70 per cent of patients are female, but not every study agrees, and the 2023 AAHA guidelines describe the pattern as inconsistent.
There is no validated DNA test, so screening parent dogs is not yet possible.

The signs: vague, and they come and go

The signs resemble ordinary upsets, so look for a pattern rather than one bad day:

poor appetite or fussy eating;
vomiting and diarrhoea that sometimes clear up by themselves;
lethargy and less interest in walks or play;
weight loss with no obvious reason;
weakness or trembling;
sometimes more drinking and urinating.

A key clue is that stress tends to make things worse. A house move, a stay in boarding kennels, a long journey or a night of fireworks can set off an episode. If your dog repeatedly goes downhill around such events, tell your vet.

Emergency: the Addisonian crisis

Sometimes the disease tips over suddenly. In an Addisonian crisis blood pressure drops, potassium in the blood climbs and the heart rate can become dangerously slow. Blood sugar may fall too. You may see collapse, severe weakness, heavy vomiting or diarrhoea, sometimes bloody. This is life-threatening, so go to an emergency vet immediately. Most dogs recover well with intravenous fluids and hormone replacement in the clinic.

How the vet makes the diagnosis

Routine blood tests often give the first hint, such as an odd sodium to potassium ratio, but they are not specific enough on their own. The diagnosis is confirmed with an ACTH stimulation test. The vet takes a blood sample, injects synthetic ACTH (the signal that normally switches the adrenal glands on) and takes another sample one to two hours later. If cortisol barely rises, the diagnosis is made. A low baseline cortisol on the first sample can also help rule Addison's out, which is why vets often check it early.

Treatment: lifelong, and very manageable

Addison's cannot be cured, but the missing hormones can be replaced:

Aldosterone is usually replaced with an injection of desoxycortone pivalate (DOCP) every few weeks, or with daily fludrocortisone tablets.
Cortisol is replaced with a small daily dose of prednisolone.

In the first months, blood checks happen about every two weeks while the dose is settled, then typically every 3 to 6 months. On predictable stress days, such as a kennel stay or another illness, specialists advise doubling the prednisolone dose. Always agree this with your own vet beforehand rather than deciding on the day.

The outlook is good news. With early diagnosis, reliable medication and monitoring, specialists call the prognosis excellent, and many dogs enjoy a normal quality and length of life. For general ageing care, see our senior Poodle care guide.

What is available where you live

United States: Percorten-V was approved by the FDA in 1998, and Zycortal followed in 2016. Both contain the same active ingredient and need a veterinary prescription, but your vet should not treat them as interchangeable.
United Kingdom: Zycortal is sold as a prescription-only veterinary medicine, and it has been on the UK market since 2016 after EU approval in 2015.
Insurance: Addison's is usually treated as a long-term condition. Lifetime policies can keep paying for it year after year if the illness starts after the policy begins and you renew without a gap, while time-limited policies often stop paying after about 12 months for the same condition. Pre-existing conditions are generally excluded. Our guide to Poodle pet insurance explains what to check.

Everyday practicalities

Sitters and boarding: leave written instructions with the medication, the stress-day dose agreed with your vet and your vet's phone number.
Travel: pack enough medication for the whole trip plus extra, and know where the nearest vet is. More in traveling with a Poodle.
Health overview: for other conditions to watch in the smaller sizes, see Toy Poodle health.

In short

In Addison's, the adrenal glands make too little cortisol and usually too little aldosterone.
Research centres on the Standard Poodle (8.6 per cent affected in one survey). There are no separate figures for the smaller sizes, but the Poodle is on breed-risk lists.
Signs are vague, come and go and worsen with stress. Collapse or severe vomiting is an emergency.
The ACTH stimulation test confirms the diagnosis.
Lifelong hormone replacement and regular checks give an excellent outlook.

This article does not replace a vet. If something about your dog worries you, have him examined.