An unusual case of uterus didelphys in an infertile mare with mosaic X-chromosome aneuploidy

A 3 year old Irish Cob maiden mare of normal size was referred at the Centre Hospitalier Universitaire Vétérinaire, University of Montreal, Faculty of Veterinary Medicine because of fertility problems and the possible presence of two cervices. The external genitalia appeared normal. Examination of the internal reproductive tract revealed normally functioning ovaries and two tubular structures compatible with cervices were identified on the pelvic floor. Endoscopy of the cranial vagina confirmed the presence of two cervices. Chromosome analysis revealed mosaic aneuploidy of the X chromosome (mos 63, X/64, XX). No treatment was available for either of the anomalies diagnosed and the mare was discharged. This report highlights the importance of using diagnostic tests in addition to clinical examination in cases of equine infertility.