Rhino Horn ‘Infusion’ Claims Under Scrutiny in South Africa

Scientists are refuting claims that rhino horns can be "infused" with  toxins. Photo By Steve Evans via Wikimedia Commons
Scientists are refuting claims that rhino horns can be “infused” with toxins. Photo by Steve Evans via Wikimedia Commons

First, they called it rhino horn “poisoning”, then “infusion”, and now “devaluation”.

The Rhino Rescue Project in South Africa says its controversial anti-poaching measure — injecting dye and toxins into the horns of living rhinos — makes the horns hazardous to end users.

But now, a tide of doubt seems to be rising.

The Rhino Rescue Project claims that consumption of a rhino horn “infused” with its “toxic, but non-lethal” cocktail may cause “severe nausea, vomiting and convulsions (all dosage-dependent)”.

Since its inception in 2010, the Rhino Rescue Project has “infused” the horns of more than 200 rhinos, charging around R6500 – R6800 (US $608 – $636) per treatment. Also in 2010: An unfortunately-timed hoax claiming that a Thai man had died after consuming poisoned rhino horn “from a private game farm somewhere in southern Africa” was making the rounds on social media.

Now, four years later, scientists are refuting the claims made by Rhino Rescue Project.

A new unpublished paper[1], expected to appear in a well-known scientific journal, makes the case that “chemical horn infusions” have not been studied or evaluated. The authors point out that the compounds used in the Rhino Rescue Project’s horn injections ( “anti-parasitic drugs used to treat ectoparasitic infestations where parasitic organisms primarily live on the surface of the host”) are non-toxic to humans.

“Most commercially available ectoparasiticide products are relativity safe to humans and unlikely to have any serious health consequences in the quantities ingested from known rhino horn products.”

In a promotional video, the Rhino Rescue Project says that a rhino’s horn is “almost hollow, like holding a bunch of straws in your hand” and that the chemical cocktail is distributed throughout the horn’s interior, via these “straws”.

“It’s quite easy, when you apply the right pressure, to infuse a liquid all the way up those straws, from the bottom to the top of the horn. And that’s what happened during the infusion part of the procedure.”

However, upon further examination, there appears to be a lack of supporting evidence for this claim:

“We could find no literature assessing the efficiency of this procedure in distributing chemical compounds evenly through the cornified epidermal tissue of horn. Horn structure suggests differential resistance to wear, which predicts differential distribution of the chemical compounds following infusion. We could also not find literature on high infusion pressure that could damage keratinocyte tubules with consequences for the future strength of the horn. Even so, higher core melanin concentration predicts weaker treatment penetration in the longitudinal centre of the horn. There is thus some chance that suitable core areas remain and are still available for human consumption.

When queried on this issue, the Rhino Rescue Project indicated that they had not cut through a treated horn to ascertain if the coloured dye actually infused through the horn as they claimed.”

Toxicology expert Dr. Gerhard Verdoorn of Griffon Poison Information Centre told Primedia Broadcasting’s John Maytham that poisoning rhino horns “doesn’t work at all”. Dr. Verdoorn explained that horn is not living material and that dyes and chemicals cannot penetrate the horn as claimed by the Rhino Rescue Project.

“It’s a non-starter,” he says.

Rhino horn trade expert, Dr. Tom Milliken of TRAFFIC explained on the South African news program Carte Blanche that “infusion” is not necessarily going to deter buyers, as there is a “whole range of products” being created from rhino horn.

“If you’ve got a little cavity in the middle of your horn that is discolored — they’re making bracelets, they’re carving things out of horn — that would be very easy just to work around.”

In response to the recent criticisms set forth in the paper and on the August 31, 2014, episode of Carte Blanche, the Rhino Rescue Project points to a South Africa National Parks (SANParks) conspiracy: “[D]ue to circumstances largely beyond our control, RRP (quite unintentionally) stood in the way of SANParks selling its horn stockpiles and/or its live rhinos. Instead of exhibiting a willingness to collaborate, SANParks chose to deal with this problem by discrediting RRP. And so, a promising research project that could have contributed greatly towards South Africa’s anti-poaching efforts has been interrupted before we could reach definitive conclusions – and lambasted for a lack of definitive conclusions”.

Julian Rademeyer, author of “Killing for Profit: Exposing the Illegal Rhino Horn Trade”, remains skeptical of the Rhino Rescue Project.

People spent money on a myth and journalists who should have known better fell for it and reported on it unquestioningly. Rhino owners bought into a product they believed worked. They believed it infused the horn. It would seem, from the available evidence, that they were misled. Other than to produce a 45 page document that tries to cast doubt on the SANParks paper, the RRP have produced no hard scientific evidence that infusion works. To tackle poaching we need sound ideas that are based on solid research and hard facts.”

Rademeyer warns that by creating “poisoned” horn, traders “would pay more for horn they believe to be untreated. Which just makes the situation worse”.

1. Are chemical horn infusions a poaching deterrent or an unnecessary deception?
Sam Ferreira,1 Markus Hofmeyr2, Danie Pienaar1& Dave Cooper3

1 Scientific Services, SANParks, Skukuza
2 Veterinary Wildlife Services, SANParks, Skukuza
3 Veterinary Wildlife Services, Ezimvelo KZN, Hluhluwe



Rhishja Cota-Larson

I am the founder of Annamiticus, and I work as an independent Wildlife Trade and Communication Design Consultant. I have journeyed to the streets of Hanoi to research the illegal wildlife trade, and to the rainforests of Sumatra and Java to document the world’s rarest rhinos. I am a Co-Chair of the SSN Pangolin Working Group. At CITES meetings, I collaborate with colleagues from around the world to lobby in favor of protecting endangered species. I am a Wildlife Trade and Trafficking Consultant for the upcoming documentary The Price, the host of Behind the Schemes and author of the book Murder, Myths & Medicine. I enjoy desert gardening, herping, reading, designing, and walking with my dogs.