True hermaphroditism in a wild sheep: A clinical report.

Intersexuality in sheep is rare, with the freemartin anomaly being the most common. We describe here a true hermaphrodite in a wild sheep. An F(1) wild sheep ewe of Argali-mouflon X Mexican desert bighorn breeding was bred to an F(1) ram of the same breeding. A single lamb was born with the external appearance of a normal female. The lamb grew faster than its female cohorts, and by 6 months of age exhibited the aggressive behavior, size, coloration and horn development associated with males. Phenotypically, the intersex had female external genitalia with an enlarged clitoris. A human chorionic gonadotrophin (hCG) response test was performed when the intersex was 1-year-old and serum testosterone, progesterone and estradiol levels were compared to the response of a normal female and male of similar age and breeding. An exploratory celiotomy revealed two gonadal-like structures associated with a female reproductive tract. Histopathology of the structures revealed spermatogenically inactive testicular vessels and ovarian tissue with primary follicles. The reproductive tract was complete with two uterine horns and a cervix. The intersexuality is attributed to an XX/XXY mosaic.