Addison’s Disease (Hypoadrenocorticism)
An endocrine deficiency where the adrenal glands fail to produce vital steroid hormones (cortisol and aldosterone).
💬 In Plain English
Often called “the great imitator,” Addison’s disease occurs when the adrenal glands are damaged—usually by the dog’s own immune system—and stop producing two critical hormones: aldosterone (which balances sodium and potassium) and cortisol (which maintains blood sugar and handles stress). Without these hormones, dogs experience waxing and waning lethargy, vomiting, diarrhea, trembling, and life-threatening dehydration crises.
🔬 Clinical & Technical Depth
For Vets & TechniciansFormal Clinical Definition
Primary hypoadrenocorticism involves immune-mediated destruction of both the adrenal cortex zona glomerulosa and zona fasciculata, resulting in mineralocorticoid and glucocorticoid deficiency. Severe hyperkalemia and hyponatremia produce hypovolemia, bradycardia, and cardiogenic shock.
Why Veterinarians Use It
Veterinarians consider Addison’s when young-to-middle-aged dogs present with intermittent gastrointestinal upset, unexplained lethargy, or characteristic electrolyte abnormalities (high potassium and low sodium).
Clinical Context Encountered
Encountered either as a chronic, puzzling illness with intermittent episodes following stress, or acutely as an emergency “Addisonian crisis” marked by severe collapse and bradycardia.
Clinical Reference Guide (Medical Condition)
- •Acute Addisonian Crisis is a medical emergency: profound weakness, hypothermia, slow heart rate (bradycardia), and collapse require immediate IV fluid resuscitation and electrolyte correction.
❓ Questions to Ask Your Veterinarian
Take these actionable questions with you to your next clinic visit or appointment:
- 1Does my dog have typical Addison’s (both mineralocorticoid and glucocorticoid deficiency) or atypical Addison’s (glucocorticoid only)?
- 2What was the sodium-to-potassium ratio on initial labwork?
- 3Do you recommend monthly injectable DOCP (Zycortal/Percorten-V) or daily oral fludrocortisone?
- 4How should I adjust my dog’s daily physiologic prednisone dose during stressful events like travel or surgery?
Academic & Clinical References
- ACVIM Consensus Statement on the Diagnosis and Management of Hypoadrenocorticism in DogsOrganization: American College of Veterinary Internal Medicine (ACVIM) • Accessed: 2026-01-10https://www.acvim.org