Cushing's (HAC) Diagnostic

Species & Test

nmol/L

Default 40 nmol/L. Use your laboratory's cut-off.

Dose reminder

Dexamethasone 0.01 mg/kg IV (dog). Sample at 0, 4 and 8 hours.

Low-Dose Dexamethasone Suppression (LDDS)

nmol/L
nmol/L

Used to assess the PDH pattern (below 27.6 nmol/L or below 50% of basal)

nmol/L

Positive if above 40 nmol/L

Interpretation

Low-Dose Dexamethasone Suppression (LDDS)

Not interpreted

Enter the 8-hour cortisol (and basal and 4-hour to assess the suppression pattern).

Next Steps

If LDDS positive: abdominal ultrasound to assess the adrenal glands. If the suppression pattern is consistent with PDH, consider trilostane. If PDH cannot be differentiated, consider abdominal ultrasound, endogenous ACTH or HDDS. Recheck 10 to 14 days after starting trilostane.

This calculator is intended as a guide for use by veterinary professionals only. It is not a substitute for professional interpretation, diagnosis, or treatment. Calculations may not be accurate for all individuals or circumstances. Always use professional judgement and verify all calculations before use in clinical practice.