The veterinary nonsteroidal anti-inflammatory drug diclofenac was banned in several South Asian countries after the product was linked to mass deaths of vultures there. But diclofenac was recently approved in Spain and Italy--sparking an outcry from an international team of veterinarians, conservationists, and biologists, who argue that the drug will put Europe's vultures at risk of extinction.
In an editorial published online recently by the journal Science, the researchers urge the worldwide scientific community to band together to weigh the benefits of veterinary drugs against the risks they might pose beyond the populations of animals that they're meant to help.
In the case of diclofenac, which is used mostly to treat livestock, the vultures ingested the drug by eating the carcasses of dead animals that had been treated with it. Even though the carcasses harbored tiny traces of diclofenac, it was enough to cause the near-extinction of three species of South Asian vultures.
Spain approved diclofenac in 2013 for use in cattle, pigs, and horses, but the authors of the Science paper believe the drug should be banned across Europe. "I was shocked when I first heard that diclofenac had been authorized for use in--of all places--Spain, which is a stronghold for vultures in Europe," said Thijs Kuiken, professor of comparative pathology at the Erasmus Medical Center in the Netherlands, in a press release from the University of Nottingham in the U.K. "This example shows that we need to radically change the way we deal with pharmaceuticals, both those used in human and veterinary medicine."
Clearly, European drug authorities agree. On Friday, the European Medicines Agency (EMA) issued a report confirming that vultures in the EU are at risk from ingesting diclofenac residues. The EMA reviewed a wide range of risk-assessment measures, from adding warnings to the drug's label to withdrawing it from the market altogether, according to a press release from the agency. The report was sent to the European Commission, which will determine next steps.
Vultures play an important role in all ecosystems, but are particularly important in Spain, the authors argue. They remove more than 8,000 tons of livestock carcasses a year there, which helps control pests and disease, in addition to saving the economy €1.5 million, they say.
The scientists conclude by recommending worldwide stewardship of veterinary drugs to promote environmental sustainability and to prevent off-target effects to humans and the environment. "This is and will continue to be an issue of increasing concern for a wide variety of [veterinary pharmaceuticals], and one for which there needs to be greater responsibility taken across the range of stakeholders," said University of Nottingham veterinarian Lisa Yon, who also serves as chair of the European Wildlife Disease Association.
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