Which diagnostic test would answer whether a dog’s adrenal glands are functioning normally?

The ACTH stimulation test is a specific diagnostic procedure used to assess the function of the adrenal glands, particularly in relation to conditions such as Addison's disease (adrenal insufficiency) or Cushing's disease (hyperadrenocorticism). This test involves measuring the levels of cortisol in the dog’s blood before and after the administration of adrenocorticotropic hormone (ACTH). If the adrenal glands are functioning normally, the administration of ACTH will stimulate the glands to produce an appropriate increase in cortisol levels.

Other tests have different purposes. A complete blood count (CBC) provides valuable information about the overall health of the dog and can indicate infections or blood disorders, but it does not specifically assess adrenal function. A urinalysis can help detect metabolic issues and kidney function but lacks direct relevance for adrenal gland activity. Biopsy, while useful for diagnosing cancer or other tissue conditions, is not appropriate for evaluating adrenal function directly. Thus, the ACTH stimulation test is the most reliable and targeted method for determining if a dog's adrenal glands are operating normally.