Addison's Disease in Dogs: Signs, Crisis and Treatment

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

Addison's disease is sometimes called the great pretender, because its signs can look like many other illnesses.

What it is

The adrenal glands produce cortisol and aldosterone, hormones that manage stress, blood pressure and electrolytes. In Addison's disease, the glands fail to produce enough, usually from immune-mediated damage. Without these hormones, the body cannot cope with stress and electrolyte balance is disrupted.

Who is affected

Young to middle-aged dogs, more often females. Standard poodles, bearded collies, Great Danes, Portuguese water dogs, West Highland white terriers and others are over-represented, suggesting a genetic component.

Signs

• Vomiting and diarrhea, sometimes with blood
• Lethargy and weakness
• Poor appetite and weight loss
• Trembling and shivering
• Increased thirst and urination
• Waxing and waning illness that improves with fluids or stress relief

See dog vomiting causes and dog lethargy causes.

Addisonian crisis

A crisis can cause collapse, a slow heart rate, shock and dehydration. It is a life-threatening emergency that needs immediate veterinary care with fluids and hormone replacement. Dogs often respond quickly to treatment.

Diagnosis

Vets may see low sodium and high potassium on bloodwork, but not always. The ACTH stimulation test confirms the diagnosis. Additional tests rule out similar conditions. See dog bloodwork explained.

Treatment

• Emergency care: intravenous fluids, steroids and monitoring during a crisis
• Long-term mineralocorticoid replacement, using daily tablets or injections of desoxycorticosterone pivalate every few weeks
• Glucocorticoid replacement with prednisone or similar, with doses increased during stress
• Regular monitoring of electrolytes and kidney values

Living with Addison's

1. Give medications reliably.
2. Know stress-dose plans from your vet for travel, boarding or illness.
3. Watch for vomiting or lethargy and call early.
4. Keep rechecks.
5. Carry information about the condition.

Stress and travel

Stressful events can trigger crises. Ask your vet for an action plan, and bring medications, records and your vet's contact details. Tell boarding staff and groomers about the condition.

Prognosis

With proper treatment, most dogs have a normal life expectancy and quality of life. Consistent monitoring is key.

Common mistakes

• Missing diagnosis because signs come and go
• Stopping or missing medication
• Not adjusting during stress
• Skipping blood tests

Troubleshooting

• My dog vomits his medication: call your vet immediately.
• My dog is lethargic again: check electrolytes.
• Injection dates are tricky: set calendar reminders.

A simple plan

1. Learn the signs.
2. Get the ACTH stimulation test.
3. Start replacement.
4. Monitor regularly.

Real-life examples

A standard poodle collapses and is diagnosed after emergency care, then thrives on treatment. A Great Dane's recurrent vomiting is finally explained by testing. A terrier on injections has stable electrolytes for years. Early recognition makes a difference.

Staying prepared

Keep an emergency plan and medication supplies on hand.

Questions to ask your vet

Ask which replacement option is best for your dog, how often electrolytes will be rechecked, how to adjust prednisone for stress and what early signs of an impending crisis to look for. Ask for a written emergency plan, plus medications you can keep at home for urgent use.

Everyday routines

Create a medication schedule using phone alarms, and keep a spare supply in case of travel delays. Offer consistent meals and gentle exercise, and avoid situations known to stress your dog. Keep a diary of appetite, stool, energy and any triggers so changes stand out early.

Boarding and sitters

Pet sitters should know the condition, the medication schedule and the signs that need a call to the vet. Leave written instructions, your vet's number and an emergency clinic's details. Make sure someone can give injections if your dog is on them.

The takeaway

Addison's disease is serious but very manageable. Recognize vague signs early and keep up with medication and checks.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.