Male pseudohermaphroditism in a pug dog with ambiguous external genitalia: Clinical, surgical and histopathological findings

Abstract A juvenile pug dog of 2 years of age was presented with the chief complaint of a mass protruding from the presumed vulvar opening in the perineal region. Palpation of the protruded mass revealed a bony component inside. The animal was reared as a female since birth and has not exhibited oestrus behaviour yet. The urethral opening was located within the vulvar region of the perineum and was clearly separate from the protruding mass. Radiographic examination confirmed a structure resembling os‐penis/os‐clitoridis, raising suspicion of a disorder of sexual development. Abdominal ultrasonography revealed two intra‐abdominal testicles. Exploratory laparotomy confirmed the presence of bilateral testicular tissue associated with ambiguous external genitalia. Surgical excision of the gonads and abnormal external genital structure (os‐clitoridis) was performed. Histopathology confirmed testicular tissue with seminiferous tubules lined by Sertoli cells, with the absence of ovarian structures. Based on the presence of testes with conflicting external sex, the case was diagnosed as male pseudohermaphroditism with ambiguous external genitalia.