Cushing's Disease in Dogs: Understanding Hyperadrenocorticism
Cushing's disease — technically hyperadrenocorticism — is a condition where the body produces too much cortisol, the primary stress hormone. It develops gradually, which is why the early signs are easy to dismiss as normal aging. The classic combination of excessive thirst, a pot belly, hair loss, and ravenous hunger in a middle-aged or older dog should trigger a vet conversation. This guide explains what to look for and the testing and treatment landscape; diagnosis and treatment decisions belong with your veterinarian.
| Sign | What It Looks Like |
|---|---|
| PU/PD | Drinking and urinating much more than usual |
| Polyphagia | Ravenous appetite, always hungry |
| Pot belly | Pendulous, enlarged abdomen |
| Hair loss | Symmetrical, often over trunk; skin may darken |
| Skin changes | Thin skin, calcinosis cutis (calcium deposits) |
| Panting & lethargy | Excessive panting, reduced exercise tolerance |
Testing: More Involved Than a Single Blood Test
Diagnosing Cushing's requires specific testing — routine bloodwork shows changes consistent with Cushing's (elevated ALP, dilute urine) but doesn't confirm it. The low-dose dexamethasone suppression test (LDDS) and the ACTH stimulation test are the primary diagnostic tools. Imaging (ultrasound) helps determine whether the cause is pituitary or adrenal. Expect multiple vet visits and a testing process that takes weeks rather than days.
Treatment Options
The most common medical treatment is trilostane (Vetoryl) or mitotane (Lysodren) — both require careful monitoring and dose adjustments, as over-treatment can cause an Addisonian crisis (a life-threatening cortisol crash). Dogs on Cushing's medications need regular rechecks (typically ACTH stim tests) every few months. Adrenal tumors may be treated surgically in appropriate candidates. The goal is controlling symptoms and protecting organ function, not eliminating the disease entirely.
Frequently Asked Questions
What are the signs of Cushing's disease in dogs?
The classic cluster: increased thirst and urination, increased appetite, a pot-bellied appearance, hair loss (often symmetrical), panting, lethargy, and skin thinning. The combination of these signs together should prompt a vet conversation.
What is the difference between pituitary-dependent and adrenal-dependent Cushing's?
About 85% of cases are pituitary-dependent (a tumor on the pituitary gland signals overproduction of cortisol). The remaining 15% have an adrenal tumor directly. Testing determines which type, as treatment differs.
Is Cushing's disease fatal in dogs?
Untreated, Cushing's progressively damages multiple organ systems and shortens lifespan. With appropriate treatment (medical or surgical), many dogs live comfortably for years. The disease is managed, not cured.