The case for banning diclofenac and the vanishing vultures

Abstract

Critically endangered vulture species like Gyps (Gyps bengalensis, G. indicus and G. tenuirostris, constituting 99 per cent of the total vulture population) are under persistent threat from non-steroidal diclofenac and its isomers, despite it being banned since 2006. Livestock drugs such as these continue to threaten the existence of vultures. Diclofenac is a generic drug available over-the-counter and is approved for human use in treating conditions like minor aches, pains and fevers. India is the third largest drug manufacturer in the world and produces diclofenac in bulk for human consumption. Regrettably, it is often diverted illegally for veterinary purposes, often having dire consequences. Vultures are vital avian raptor species, providing an important ecosystem cleaning service, renowned for their crucial scavenging abilities. However, when they feed on dead animal carcasses treated with diclofenac, the birds succumb to kidney failure and visceral gout as a result. That said, after the much needed diclofenac ban in 2006, rapid vulture decline has slowed down, providing some hope for these birds. There is still some way to go, however, as research shows the drug has still not been completely eradicated from the vultures’ food supply. Further efforts are thus still very much required to fully implement the ban. In addition to illegal diclofenac usage, drugs with similar properties (e.g. aceclofenac and ketoprofen) are gaining momentum in the marketplace. It is predominantly within developing nations that inadequate systems exist for regulating drug usage, making the very purpose of banning diclofenac often redundant. This paper argues that more scrupulous monitoring and cross-checking of veterinary drugs such as ketoprofen, aceclofenac and meloxicam is necessary, whilst also arguing that research should be encouraged to focus on toxicities of such drugs to non-target animals like scavengers. Stringent banning of toxic killer drugs as well as interim measures like captive breeding, provision of supplemental food at ‘vulture restaurants’ (areas where fresh and poison-free meat and/or carcasses are provided) and ‘vulture safe zones’ integrated with intensive conservation campaign efforts are imperative if Asian vultures are to be safe.