Dirty Dose: Study Reveals Rhino Horns Contain More Soil Than Minerals, Debunking Medicinal Value Myth

Poachers target rhinoceroses for their horns, which are considered valuable based on the belief that they have medicinal properties, but a new study from scientists at the Cincinnati Zoo and Botanical Garden found that rhino horns contain more dirt than medically relevant minerals.

The study, led by scientists from Cincinnati Zoo & Botanical Garden’s Lindner Center for Conservation & Research of Endangered Wildlife (CREW), found that although rhino horn does contain essential trace minerals people require for good health, their concentrations are too low to be of any benefit, and some of the minerals are known to be toxic.

“In fact, people ingesting rhino horn products could actually be getting a dose of dirt since soil is embedded in the external surface of the horn,” said Terri Roth, director of CREW and director of the American Institute of Rhinoceros Science (AIRS). “Rhinoceros horn also contains some potentially toxic minerals such as lead and arsenic, but their concentrations are also low.”

Researchers hope their study, funded by the Institute of Museum and Library Services (IMLS) and published recently by Scientific Reports, will help deter poaching, giving the threatened species a better hope for survival.

Scientists didn't initially set out to dispel myths about the medicinal value of horns, they were instead hoping to find out whether horns could offer insights into rhino health.

Along with mineral analyses conducted by study co-authors at the Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Michigan State University, CREW scientists, with assistance from the Cincinnati Museum Center (CMC), performed DNA testing to identify sex, species, and relatedness of the individual horns.

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Researchers were hoping to determine if "the mineral content of rhino horn could be used as a potential, non-invasive means of monitoring rhino health."

“Poaching is driven by demand for the horns, and much of that demand comes from the belief that they contain medicinal properties to cure a plethora of illnesses,” Roth said. “Our research on multiple samples of rhino horns helps to dispel that myth and, therefore, could help rhino conservation efforts in ways we had not imagined when we began studying horn minerals for rhino health monitoring.”

TMX contributed to this report.