Endogenous ACTH use in diagnosis of Cushing's and Addison’s disease

Testing is often complicated and confusing when confirming hyperadrenocorticism (Cushing’s disease) and hypoadrenocorticisim (Addison’s Disease) in dogs. This lecture provides a review of traditional adrenal function tests (basal cortisol, ACTH stimulation testing and dexamethasone suppression testing) and introduces the use of endogenous plasma ACTH assay to provide an alternate diagnostic approach to hyperadrenocorticism and hypoadrenocorticism.

• Upon completion, participants will understand the differences between and indications for use of various adrenal function tests, including basal cortisol, ACTH stimulation and dexamethasone suppression testing in dogs.
• Upon completion, participants will be introduced to a simplified approach using canine endogenous ACTH to diagnose and differentiate pituitary-dependent vs adrenal-dependent hyperadrenocorticism.
• Upon completion, participants will be introduced to a simplified approach using canine endogenous ACTH and cortisol-to-ACTH ratio (CAR) to diagnose canine hypoadrenocorticism.