Canine hyperadrenocorticism and dermatology: cutaneous manifestations and the differential diagnosis between true Cushing's and functional hypercortisolemia

Narrative technical review of the dermatological manifestations of canine hyperadrenocorticism (HAC) and its differential diagnosis from functional hypercortisolemia (pseudo-Cushing). The work describes the characteristic cutaneous picture —non-pruritic bilaterally symmetrical alopecia, thin and hypotonic skin, comedones, calcinosis cutis, hyperpigmentation, poor wound healing, and recurrent opportunistic infections— and its pathophysiological mechanism of glucocorticoid immunosuppression. It addresses a frequent clinical problem: chronic stress and non-adrenal illness raise cortisol, reproduce part of the picture, and generate false positives on functional tests, as the ACVIM consensus warns. A practical guide to the differential diagnosis is proposed, based on the concordance of the complete clinical picture and a diagnostic sequence that protects the patient from overdiagnosis. Narrative review without primary data; peer-reviewed sources verified at their original source. Clinical content: Dr. Jessica Ysabel Camacho García (CMVP 12434, ORCID 0009-0002-6837-5311).