Switching Drug For Livestock May Save Endangered Vultures

Meloxicam, a nonsteroidal anti-inflammatory drug, has been shown to be a safe and effective replacement for diclofenac, a widely used veterinary NSAID that has inadvertently killed tens of millions of Asian vultures on the Indian subcontinent (PLoS Biol. 2006, 4, e66).

Diclofenac was introduced for human use in the 1970s, and it later came to be used in livestock. The rapid decline of three species of vultures in Asia beginning in the early 1990s—today, more than 97% of the birds have died—perplexed scientists until diclofenac-treated livestock was identified as the culprit two years ago (Nature 2004, 427, 630). When cattle and water buffalo die, they are traditionally left for the vultures, which play a vital environmental health role by eating the carcasses. But diclofenac causes rapid kidney failure and kills the vultures.

An international team identified meloxicam as a potential replacement drug because it has similar efficacy to diclofenac and is already approved for human and veterinary use in many countries. The researchers then gave vultures oral doses of meloxicam and meat from cattle treated with the drug and found that the birds suffered no ill effects.

A ban on veterinary uses of diclofenac is being put in place in India, and programs to breed vultures in captivity are being established. But "vulture populations are declining so fast that it could still be too late," notes Rhys E. Green of the University of Cambridge, a coauthor on the PLoS Biology paper.