Vet Guide to Cushing’s Disease in Dogs 2025🐶🩺 

By Dr. Duncan Houston BVSc

Cushing’s disease, or hyperadrenocorticism, is a common endocrine disorder in middle-aged and older dogs caused by chronic exposure to high cortisol levels, either due to naturally occurring tumors or long-term steroid therapy.

📍 Types & Causes

• Pituitary-dependent (≈80%): ACTH-secreting pituitary tumor drives adrenal cortisol overproduction.
• Adrenal-dependent (≈15%): Adrenal tumor produces cortisol directly.
• Iatrogenic: Long-term corticosteroid use triggers signs similar to Cushing’s.

⚠️ Classic Clinical Signs

• Polydipsia & polyuria – drinking & peeing often (in 82–91% of cases).
• Polyphagia – increased appetite.
• Pot-bellied abdomen from fat redistribution and muscle loss.
• Panting, lethargy & muscle weakness.
• Dermatologic changes – thin, fragile skin, alopecia, recurrent skin or urinary infections, bruising, calcinosis.

🔬 Diagnostic Workflow

• Blood tests & urinalysis: reveal alkaline phosphatase elevation, dilute urine.
• Screening tests: ACTH-stimulation or low-dose dexamethasone suppression (LDDST) identify cortisol excess.
• Imaging: Abdominal ultrasound or CT to locate adrenal tumors in adrenal-dependent cases.
• Differentiate types: ACTH measurements and imaging help distinguish pituitary vs adrenal causes.

💊 Treatment & Management

• Medication:
  • Mitotane (Lysodren): Adrenal cytotoxic agent, requires monitoring.
  • Trilostane (Vetoryl): Modern 3β-HSD inhibitor favored for pituitary and adrenal cases.
  • Selegiline (Anipryl): Option for mild pituitary-dependent disease.
• Surgery: Adrenal tumor removal for isolated adrenal-dependent cases; pituitary transsphenoidal surgery is less available.
• Taper steroids: Necessary in iatrogenic cases to allow adrenal recovery.
• Supportive care: Control infections, diet & weight management, skin care, blood pressure, and monitoring of blood glucose/urine.

📈 Prognosis & Lifelong Monitoring

• With medication, many dogs live 2–3 years or more; adrenal surgery may extend survival further—pituitary cases average ~700–900 days.
• Monitor with cortisol levels post-treatment, adjust dosage carefully, and repeat testing recommended quarterly to biannually.
• Watch for complications: diabetes, hypertension, UTI, pancreatitis, and thromboembolic events.

✅ Vet Tips by Dr Duncan Houston BVSc

• 🔍 Consider Cushing’s in any middle‑aged/older dog with PU/PD, pot‑belly, thin skin, or recurrent infections.
• 📆 Use screening tests for initial diagnosis, then follow appropriately with ACTH-stim or LDDST.
• 💊 Choose trilostane for most, consider mitotane or surgery where appropriate.
• 🩺 Monitor clinical response and cortisol levels at 10–14 days after starting therapy.
• 📊 Screen for concurrent conditions—UTIs, diabetes, hypertension—for comprehensive care.

If your dog is showing signs like increased drinking, weight changes, panting, or skin problems—connect via AskAVet.com. Set treatment reminders, track symptoms, 🐾❤️