Addison’s Disease in Dogs: What You Need to Know

This pet health content was written by a veterinarian, Dr. Debora Lichtenberg, VMD. It was last reviewed November 22, 2024

If you have questions or concerns, call your vet, who is best equipped to ensure the health and well-being of your pet. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. See additional information.

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What Is Addison’s Disease in Dogs?

Addison’s disease in dogs is an endocrine condition caused by the underfunctioning of the adrenal glands, also known as hypoadrenocorticism. While rare in humans and even rarer in cats, this hormonal disorder is more commonly seen in middle-aged, female dogs, with certain breeds, such as the Standard Poodle, being overrepresented.

Dogs have two adrenal glands located near their kidneys. These glands produce essential hormones that sustain life, including:

• Mineralocorticoids
• Glucocorticoids
• Androgens

Without these hormones, a dog’s body cannot function properly. While understanding the full hormonal pathways can get complex, this article aims to break it down and simplify the topic for you.

Learn more about hypoadrenocorticism in dogs for an in-depth explanation of this condition.

Basic Facts About Addison’s Disease in Dogs

Addison’s disease in dogs comes in different forms and can develop under various circumstances. Here are some key points:

• Forms of Addison’s Disease:
  • It can be primary (most common) or secondary.
  • It may also be typical (most common) or atypical.
• Link to Cushing’s Disease:
  Addison’s disease may develop in dogs being treated for Cushing’s disease if they receive excessive medication, such as Vetoryl (trilostane) or Lysodren (mitotane).
• Progression of Symptoms:
  • Symptoms often don’t appear until 90% of the adrenal glands are destroyed.
  • A small percentage of dogs may experience an Addisonian crisis, a life-threatening emergency involving severe dehydration and near-comatose states.
• Prognosis With Treatment:
  • Once diagnosed, Addison’s disease is treatable.
  • Most dogs can lead normal, happy lives with the correct dose of medication.

By catching the symptoms early and ensuring consistent treatment, dogs with Addison’s disease can maintain a healthy and fulfilling life.

Symptoms of Addison’s Disease in Dogs

The symptoms of Addison’s disease in dogs can be vague and often mimic other conditions, which is why it’s sometimes called “the Great Pretender.”

Common Symptoms

Dogs with Addison’s disease may exhibit:

• Lethargy
• Weakness
• Anorexia
• Vomiting and/or diarrhea (learn more about vomiting in dogs)
• Gradual weight loss
• Thirst
• Shaking
• Depression

These symptoms often develop gradually, making it challenging for owners and veterinarians to recognize the disease early.

Why Do Symptoms Wax and Wane?

Symptoms can wax and wane due to stress, as dogs with Addison’s disease struggle to handle stressful situations. Stressors can range from physical to emotional, including:

• Hot weather: Read tips on keeping dogs safe in hot weather.
• Exertion: Activities like longer walks or excessive exercise may exacerbate symptoms.
• Emotional stress: Triggers such as thunderstorms, changes in daily routine, or separation anxiety.

The Challenge of Diagnosis

These vague, intermittent symptoms often lead to delayed diagnoses:

• Owners may dismiss signs like fatigue or mild vomiting as minor issues.
• Veterinarians might not immediately suspect Addison’s due to its rarity.
• Some clients decline recommended blood work if their dog doesn’t seem seriously ill.

Recognizing stress as a trigger and monitoring your dog closely can help you spot potential signs of Addison’s disease earlier.

Addisonian Crisis: A Life-Threatening Emergency

An Addisonian crisis is a critical condition that occurs when the adrenal glands suddenly stop producing vital hormones. This acute phase of Addison’s disease requires immediate medical attention and is considered a true emergency.

Symptoms of an Addisonian Crisis

Dogs experiencing an Addisonian crisis may show severe symptoms such as:

• Inability to stand
• Mental depression, ranging from lethargy to near-comatose states
• Severe, life-threatening dehydration
• Cardiac abnormalities caused by electrolyte imbalances
• Shock

Emergency Treatment for Addisonian Crisis

If your dog exhibits these symptoms, they must be rushed to a veterinary hospital immediately, preferably one with a critical care unit. Rapid diagnosis and treatment are essential.

Treatment typically involves:

• Intravenous fluids to address dehydration
• Glucocorticoid supplementation to replace missing hormones
• Close monitoring of blood pressure and heart function

With prompt and intensive care, most dogs can recover from an Addisonian crisis and resume normal management of their condition.

How Is Addison’s Disease Diagnosed in Dogs?

Diagnosing Addison’s disease in dogs involves identifying key abnormalities through tests and evaluations. Early diagnosis can make a significant difference in managing the condition.

Diagnostic Steps and Clues

1. Blood Work
   • A chemistry profile and complete blood count often provide significant clues.
   • Electrolyte imbalances are common, with about two-thirds of affected dogs showing:
     • High potassium (leading to potential cardiac abnormalities)
     • Low sodium
2. Kidney Function
   • Kidney function appears abnormal in 95% of affected dogs, often resulting in a misdiagnosis of chronic kidney disease.
   • Treatment for Addison’s usually restores kidney function to normal.
3. ACTH Stimulation Test
   • This test, completed in approximately one hour, confirms the diagnosis of Addison’s disease. Learn more about the ACTH stimulation test here.
4. Other Indicators
   • A slow heart rate or weak pulses may be observed.
   • Radiographs: The heart may appear small on X-rays due to severe dehydration. Learn more about radiographs in pets.
   • EKG Results: Electrocardiograms often reveal abnormalities linked to high potassium levels.

Prompt diagnosis through these methods allows for effective treatment and management of Addison’s disease in dogs.

How Is Addison’s Disease Treated in Dogs?

While Addison’s disease in dogs is not curable, it is highly manageable with proper lifelong treatment. The key to management is replacing the hormonal substances that the body is unable to produce on its own.

Hormone Replacement Therapy

1. Glucocorticoids
   • These hormones are replaced with a drug called prednisone, a type of corticosteroid.
   • Once the condition is regulated, many dogs may:
     • Stop prednisone treatment entirely.
     • Use prednisone only during times of stress.
2. Mineralocorticoids
   • These can be provided in two forms:
     • Daily pill form
     • Injections administered every 3–4 weeks (preferred by most owners).
   • Mineralocorticoid supplementation is required for life to maintain balance.

Learn more about hormonal replacement therapies for Addison’s disease.

Long-Term Outlook

With proper treatment, dogs with Addison’s disease can lead happy, healthy lives. Regular checkups and monitoring are essential to adjust medications and prevent complications.

Addressing Concerns About Prednisone Side Effects

Prednisone often carries a reputation for causing side effects, but when used to treat Addison’s disease in dogs, it works very differently compared to other conditions.

Why Prednisone Is Safe for Dogs With Addison’s Disease

• In conditions like allergies, autoimmune diseases, or cancer, prednisone is prescribed to add glucocorticoids to an already balanced system. This additional dose can lead to side effects.
• However, in dogs with Addison’s disease, prednisone is not “extra” — it replaces glucocorticoids that the body cannot produce on its own.

Minimal Prednisone Dosages

Dogs with Addison’s disease usually require only a small amount of prednisone to feel good. If side effects occur, they can often be managed by:

• Reducing the dose further.
• Switching to alternate-day dosing.
• Trying another type of steroid.

To learn more about prednisone and its effects, check out this comprehensive guide.

When used appropriately for Addison’s disease, prednisone is a safe and effective treatment that helps maintain your dog’s health and quality of life.

Managing Stress in Dogs With Addison’s Disease

Stressful situations can send a stable Addisonian into a crisis.

Stress could be caused by:

• Boarding
• Holidays
• Travel
• Fireworks or thunderstorms
• Veterinary visits or procedures
• Loss of a caregiver

Vets recommend giving prednisone during these times to Addisonian dogs who are not regularly receiving it, as well as increasing the prednisone dose in dogs who take a small amount daily.

In a normal dog, stress induces the body to release excessive glucocorticoids to deal with the stressful situation.

For an Addisonian who becomes stressed, though, the body cannot produce those glucocorticoids to help deal with the stress. These dogs may go into crisis in times of stress if not given prednisone.

Which Dog Breeds Are Most Likely to Get Addison’s Disease?

Although any dog can develop Addison’s disease, around 70% of affected dogs are female. About 80% are younger than 7 years old.

Breeds with an increased risk of Addison’s disease include:

• Standard Poodle
• Soft-Coated Wheaten Terrier
• West Highland White Terrier
• Rottweiler
• Great Dane
• Bearded Collie
• Portuguese Water Dog
• Labrador Retriever
• Leonberger
• Great Pyrenees
• Pomeranian
• Cairn Terrier
• American Cocker Spaniel
• Nova Scotia Duck Tolling Retriever

Prognosis Is Excellent, but the Medication Isn’t Cheap

With proper treatment, dogs with Addison’s disease can live long, happy, and normal lives. However, managing this condition can be costly, particularly for owners of larger breeds.

The Cost of Addison’s Treatment

• Mineralocorticoid Replacement:
  • Medications like Percorten (injection) and Florinef (oral tablets) are essential but can be expensive, especially for large dogs.
  • Veterinarians often work closely with clients to determine the lowest effective dosage to balance cost and health.
• Financial Strain:
  • The ongoing cost of medications over 7–8 years can be overwhelming for some pet owners.
  • Unfortunately, this financial hardship has led some to consider euthanasia.

A Balanced Approach to Treatment

For families facing financial difficulties, veterinarians aim to:

• Minimize the medication dosage while ensuring symptoms remain under control.
• Avoid under-medicating, which could lead to an Addisonian crisis and further expenses.

With consistent monitoring and proper stress management, dogs with Addison’s disease can lead fulfilling lives. Hopefully, as treatments evolve, medication costs will become more affordable, making this condition easier to manage for all families.

Frequently Asked Questions (FAQ)

References

• Klein, Susan C., DVM, and Mark E. Peterson, DVM, DACVIM. “Canine Hypoadrenocorticism: Part I.” Canadian Veterinary Journal 51, no. 1 (January 2010): 63–69. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2797351/.
• Lathan, Patty, DVM, DACVIM, and Ann L. Thompson. “Management of Hypoadrenocorticism (Addison’s Disease) in Dogs.” Veterinary Medicine 9 (February 2018): 1–10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6055912/.
• “Vetoryl Capsules (Trilostane).” Dechra Veterinary Products. 2015. https://www.dechra-us.com/Admin/Public/Download.aspx?file=Files%2FFiles%2FSupportMaterialDownloads%2Fus%2F01TB-VET50030-0615.pdf.
• Webb, Craig, DVM, PhD, DACVIM, and David Twedt, DVM, DACVIM. “Acute Hepatopathy Associated With Mitotane Administration in a Dog.” Journal of the American Animal Hospital Association 42, no. 4 (July–August 2006): 298–301. https://pubmed.ncbi.nlm.nih.gov/16822769/.
• Macintire, Douglass, DVM, DACVIM, DACVECC. “Addisonian Crisis (Proceedings).” dvm360. Aug. 1, 2008. http://veterinarycalendar.dvm360.com/addisonian-crisis-proceedings.
• Hoskins, Johnny D., DVM, PhD, DACVIM. “Testing for Addison’s Disease.” dvm360. Jan. 1, 2009. http://veterinarynews.dvm360.com/testing-addisons-disease?id=&sk=&date=&pageID=2.
• Edwards, Scott H., BVMS, PhD. “Corticosteroids.” Merck Veterinary Manual. https://www.merckvetmanual.com/pharmacology/anti-inflammatory-agents/corticosteroids.
• Schaer, Michael, DVM, DACVIM, ACVECC. Clinical Medicine in the Dog and Cat. Manson Publishing Ltd. 2002.