Mosaic 35,X/36,XY karyotype and intersex in a red panda (Ailurus fulgens fulgens)

A zoo-bred Himalayan red panda (Ailurus fulgens fulgens) was diagnosed as a presumptive intersex on clinical examination at 4-mo-of-age. The phenotype was predominantly female but showed a large anogenital distance and bilateral ischial swellings. Based on cytogenetic evaluation, the karyotype was mos35,X/36,XY, with 50% of each cell type. A grossly normal uterus and oviducts were seen with laparoscopic examination, while the gonads were smooth-surfaced, with a ramifying vascular pattern. On histopathologic examination the bulk of the gonads consisted of clumps of poorly differentiated cells, with just a thin rim of ovarian tissue under the region covered by the fimbriae of the oviduct.