Role of veterinary diclofenac in decline of vulture populations in South Asia

摘要

Gyps vulture populations declined by more than 98% across the Indian subcontinent in last one decade. Post-mortem examination showed that the majority of vultures found dead in the wild had a lethal accumulation of uric acid crystals in the tissues (visceral gout), due to kidney damage that prevented the elimination of this excretory product. Diclofenac, a nonsteroidal anti-inflammatory drug potentially nephrotoxic to birds, has become a widely used veterinary medicine and was identified as the causeof the decline; toxicity testing of diclofenac in four species of Gyps vulture caused dose-dependent mortality (LD_(50) of 0.225 mg kg~(-1) vulture body weight) and identical clinical signs (visceral gout) to those found in carcasses of wild birds. In carcass dumps, detectable diclofenac in 10.1% of 1848 domestic ungulate carcasses was noticed which was the important and sole cause of vulture population decline. Others causes like food availability; loss of breeding habitat and disease did not have sufficient evidence. It is now imperative that diclofenac is effectively removed from the veterinary market in South Asia as an alternative drug, meloxicam is available.