Disorders of sexual development: a case of XX sex reversal in a mixed breed dog negative for SRY (sex-determining region on the Y chromosome) gene

An 8-month mixed breed dog (from shelter) was evaluated for its abnormal external genital (enlarged os clitoris protruding externally from the vulva) condition. Dog had phenotypic female appearance. Testicular-like tissue was removed via laparoscopy-assisted gonadectomy. Genotype was determined using blood and gonadal tissue (via histology and immunohistochemistry). Dog had XX chromosomes and was negative for SRY (sex-determining region on the Y chromosome) gene.