Cushing's Disease: Diagnosis, Monitoring, and Integrative Support

Learning Objectives

• 1Recall the classic clinical signs of canine hyperadrenocorticism and the screening tests used to confirm or rule out Cushing's disease in general practice
• 2Explain the physiologic basis of PDH vs. ADH differentiation, including the mechanisms behind the high-dose dexamethasone suppression test and abdominal ultrasound findings
• 3Critically analyze the diagnostic pitfalls of Cushing's testing — including the high false-positive rate of the ACTH stimulation test, the effect of non-adrenal illness on test results, and the danger of treating a borderline result in a mildly symptomatic dog
• 4Apply evidence-based protocols for initiating, dosing, and monitoring trilostane and mitotane therapy, including recognition of early hypoadrenocorticism and the adrenal crisis response protocol
• 5Evaluate the evidence for integrative adjuncts in Cushing's disease management — including hepatic support (SAMe, milk thistle), cardiovascular risk mitigation, and acupuncture — and identify when each is most clinically useful

Course Syllabus

1. 1
   Meet Gracie: Two Years of 'Allergies and UTIs' — Then the Real DiagnosisPreview

   Opening case: Gracie, a 9-year-old spayed female Poodle mix, presenting for recurrent skin infections and her third UTI this year. Her PU/PD has been attributed to anxiety. Her pot-belly was noticed but not pursued. Today her workup reveals the diagnosis hiding in plain sight.

   6 min
2. 2
   Clinical Signs and Why Cushing's Gets Missed for Months or Years

   The classic and subtle clinical signs of HAC, the diseases that steal Cushing's presenting complaints, and how to recognize the pattern before ordering any tests

   9 min
3. 3
   The Diagnostic Algorithm: LDDST, ACTH Stim, and When to Stop Testing

   Low-dose dexamethasone suppression test vs. ACTH stimulation test — sensitivity, specificity, and correct clinical application; urine cortisol:creatinine ratio as a screening tool; when to pursue discriminating tests (HDDST, abdominal ultrasound, endogenous ACTH); the false-positive problem

   13 min
4. 4
   PDH vs. ADH: Why It Matters and How to Differentiate

   Pituitary-dependent vs. adrenal-dependent disease — frequency, prognosis, ultrasound characteristics, and why the distinction changes the conversation with owners

   7 min
5. 5
   Treatment: Trilostane, Mitotane, and How Not to Cause an Adrenal Crisis

   Trilostane — mechanism, dosing protocol (starting at 2.2–6.7 mg/kg SID), ACTH stimulation monitoring schedule, dose escalation, and when BID dosing is needed; mitotane (o,p'-DDD) — induction, maintenance, monitoring; recognizing and managing hypoadrenocorticism; the adrenal crisis emergency protocol

   15 min
6. 6
   Integrative Support and Gracie's Outcome

   Hepatic support for drug-induced and hypercortisolemia-induced hepatopathy; cardiovascular risk reduction; acupuncture and HPA axis modulation; client communication about disease monitoring; Gracie at 18 months

   8 min