Subdiagnostic Cushing's syndrome in a Labrador retriever diagnosed with progesterone‐secreting adrenocortical neoplasia and late liver metastasis

A 5‐year‐old, neutered male Labrador retriever was presented for poor hair regrowth following clipping, lethargy, exercise intolerance, polyphagia, polydipsia, polyuria and heat‐seeking behaviour. A bradyarrhythmia due to a second‐degree atrioventricular block and poor cardiac contractility was found. On abdominal ultrasound, a left adrenal mass was detected, and a functional progesterone‐secreting tumour was diagnosed and confirmed on histopathology and electron microscopy. After the initiation of inodilator drug therapy and adrenalectomy with a subsequent decline in progesterone concentrations, the clinical signs resolved. The dog was represented 2 years later with similar clinical signs. The dog's progesterone concentrations were again elevated, and a metastatic liver mass was detected on abdominal ultrasound examination and computed tomography scan. After liver lobectomy, the diagnosis was confirmed on histopathology, the clinical signs resolved, and progesterone concentrations normalised. This report describes the presentation of a dog with progesterone‐secreting adrenocortical neoplasia and late metastasis.