Ultrasonography and Computed Tomography Findings of Renal Phaeohyphomycosis in a Dog

Phaeohyphomycosis is uncommon in dogs and can involve multiple tissues.A four-year-old neutered male Bichon Frise was referred for dark-colored urine and marked weight loss after three weeks of immunosuppressive therapy.Abdominal ultrasonography revealed ill-defined, heterogeneous hypoechoic-to-anechoic regions predominantly along the lateral aspect of the right kidney, involving approximately 40% to 50% of the parenchyma, with poor corticomedullary differentiation and markedly decreased vascularity on color Doppler imaging compared with the left kidney.Computed tomography demonstrated extensive cortical destruction (approximately 70% of the right kidney) with minimal-to-absent enhancement of the affected regions and perirenal fat stranding.A right nephrectomy was performed, and histopathology confirmed multifocal pyogranulomatous nephritis with intralesional pigmented fungal elements, including pigmented hyphae.This report describes the ultrasonographic and computed tomographic findings of isolated renal phaeohyphomycosis in a dog following immunosuppressive therapy.