Vet Approved Guide: Addison’s Disease in Dogs – Signs, Causes & 2025 Treatment Tips 🐶🐾

By Dr. Duncan Houston BVSc

Addison’s Disease (aka hypoadrenocorticism) is an endocrine disorder where the adrenal glands fail to produce enough cortisol and aldosterone. It’s often called “the great mimic” since its vague, intermittent symptoms can resemble many other conditions, but early recognition and treatment can help your dog thrive. 🛡️

🔍 What Is Addison’s Disease?

In canine Addison’s, the adrenal cortex gland underperforms, leading to deficiencies in cortisol (stress hormone) and often aldosterone (electrolyte regulator). Most cases are immune-mediated, with other causes including tumors, trauma, infection, or abrupt steroid withdrawal.

📋 Who Is Most at Risk?

• Young to middle-aged dogs (average age ~4–5 years), females slightly more than males.
• Breeds predisposed: Standard Poodles, Portuguese Water Dogs, Bearded Collies, Nova Scotia Duck Tolling Retrievers, Great Danes, Labradors, West Highland Terriers. 

🩺 Common Symptoms ("The Great Mimic")

• Lethargy, weakness
• Vomiting, diarrhea
• Loss of appetite, weight loss
• Increased thirst and urination
• Trembling or shaking
• Addisonian crisis: collapse, severe vomiting/diarrhea, dehydration, bradycardia, shock†.

Signs often wax and wane, making diagnosis tricky. Intermittent “off” days, especially with GI upset, should raise suspicion.

🧪 Diagnosing Addison’s Disease

• Routine labwork may reveal electrolyte imbalance: low sodium, high potassium, sodium-to-potassium ratio < 27.
• ACTH stimulation test remains the gold standard—measures cortisol response before and after synthetic ACTH.
• Additional tests (ECG, imaging) may assess heart rate effects or rule out adrenal tumors.

🛡️ Treatment & Ongoing Management

Hormone Replacement Therapy

• Mineralocorticoid replacement: DOCP injections (Percorten‑V/Zycortal) every 3–4 weeks or oral Florinef.
• Glucocorticoid support: daily prednisone or prednisolone. Dosage is adjusted based on stress or illness.

Managing Addisonian Crisis

Hospitalization with IV fluids, emergency steroids, electrolyte stabilization, and monitoring is essential. These patients often recover rapidly within 24–48 hours when managed correctly.

Long-Term Monitoring

• Frequent bloodwork initially to adjust hormone dosages
• Electrolyte checks and stress dose adjustments as needed
• Lifestyle balance: low stress, nutrition, hydration, and caution during illness or travel

🧭 Prognosis

Once stabilized on proper hormone replacement, dogs with Addison’s can live full, healthy lives. Lifelong management is required, but the prognosis is excellent.

📱 Vet-Trusted Tools to Support Management

• Ask A Vet: Get 24/7 advice for dosage adjustments, stress management, and crisis response. 🩺

🎯 Final Thoughts

Addison’s Disease may be rare, but with timely diagnosis and consistent treatment, your dog can thrive long-term. If your dog has unexplained lethargy, vomiting, or abnormal lab results—especially electrolyte imbalances—ask your veterinarian about Addison’s. 🐾

For personalized support and peace of mind, download the Ask A Vet app today. 📲🐶