Elevated testosterone levels in a racing horse due to an XY testicular disorder of sexual development.

Abstract

A female thoroughbred successful in horse racing was positively tested for high testosterone values. This horse neither showed stallion-like-behaviour nor signs of ambiguous external genitalia. The karyotype of this horse was 2n = 64,XY and the sex-determining region of Y (SRY) PCR was positive. Hair samples tested for naturally testosterone revealed values normal for stallions, and tests for eight synthetic testosterone esters remained negative. The phenotype, ultrasonographic examination, hormone status, cytogenetic evaluation and molecular diagnostics lead to the diagnosis of an XY testicular disorder of sexual development (DSD) due to a complete androgen insensitivity syndrome. To our knowledge this is the first report about a thoroughbred in racing sports with an XY testicular disorder of sexual development. To date, intersex racing horses have never been described in thoroughbreds or a regulation for intersexes in regard to horse races has been issued.

• Authors: Claudia Dierks, Harald Sieme, Marion Piechotta, Stephanie Lehner, Jan Carlos Merkt, Hubert Uphaus, Erich Klug, Ottmar Distl
• Journal: Berliner und Munchener tierarztliche Wochenschrift (Berl Munch Tierarztl Wochenschr) 2015 Jul-Aug Vol. 128 Issue 7-8 Pg. 335-9 ISSN: 0005-9366 [Print] Germany
• PMID: 26281448 (Publication Type: Journal Article)

Chemical References

• Testosterone

Topics

• Animals
• Disorder of Sex Development, 46,XY (blood, diagnostic imaging, veterinary)
• Female
• Horse Diseases (blood, diagnostic imaging)
• Horses
• Male
• Testis (diagnostic imaging)
• Testosterone (blood)
• Ultrasonography