Bilateral Ovotestes in a Female Beagle Dog

Abstract

We report a case of bilateral ovotestes in a female beagle dog. This dog was used in a 4-week repeated-dose toxicity study and sacrificed by exsanguination at 6 months of age. Clinical observation, hematological examination, blood chemistry analysis, urinalysis and autopsy did not reveal any abnormal or drug-induced effects. Microscopically, seminiferous-like tissue was observed in the medulla of the bilateral ovaries. The morphological and immunohistochemical characteristics of Sertoli-like cells lining the seminiferous-like tubules corresponded to those of Sertoli cells in the testis. Myoid-like cells exhibiting positive reactions for alpha smooth muscle actin surrounded the seminiferous-like tubules. Therefore, the dog was regarded as a case of true hermaphroditism with bilateral ovotestes. PCR using DNA extracted from paraffin-embedded sections of the testicular parts of the ovotestis, uteri and spleen showed that the organogenesis of ovotestes in this case was not associated with the sex-determining region Y gene.