Horse Racing

Mel Evans/AP

Hermaphrodite Horses Baffle the Racing Community

May 09, 2009 08:30 AM
by Rachel Balik
Testing has discovered that a Canadian and an Australian racehorse are intersex, possessing both male and female characteristics.

Intersex Horses Race, But Don’t Reproduce

The owners of Australian racehorse What Am I assumed that he was a male. But when they tried to geld the colt, they discovered that he lacked male reproductive organs. The Courier-Mail reported that the horse, a pacer, is in fact a male with female genitalia. But he does not have the reproductive organs of a mare, either: he has no reproductive organs at all.

His owner, Basil King, said this lack means the horse is not actually a hermaphrodite, but has a special condition called “vaggintersex.” King says that Baxter, as What Am I is called at the stable, is a good runner but can be moody.

Meanwhile, authorities in the U.S. discovered that Canadian racehorse Arizona Helen was intersex when she was tested for anabolic steroids. The steroids, illegal in many states, raise testosterone levels.

Arizona Helen’s results aroused suspicion, as mares and geldings are unable to produce the elevated levels of testosterone the horse had. The Blood-Horse reported that Arizona Helen’s white blood cells revealed the horse to have “XY sex reversal.” She has testicular and vaginal tissue, but is technically male and races as a male.

Related Topic: Males of all species becoming female

In December 2008, a British study indicated that chemicals in the environment are having a profound effect on many animal species: males are developing feminine characteristics. Scientists call the chemicals, which disrupt normal levels of male hormones, “gender benders.” Hermaphroditic deer and polar bears have been discovered, and 50 percent of male fish in the British lowlands were found with eggs growing inside their testes.

Human beings have also exhibited similar changes. A study led by the Center for Reproductive Epidemiology at the University of Rochester found that baby boys who had been exposed to a chemical found primarily in plastic were born with smaller penises.

Reference: Assessing the Risk of Steroids In Race Horses and Anabolic Steroid Abuse

Slate takes a close look at how steroids affect racehorses. Although steroids are thought to harm humans, whether they harm horses is still being debated. has a full information page on anabolic steroid abuse in humans.

Most Recent Beyond The Headlines