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

Abstract

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 non- steroidal anti-in? ammatory drug potentially nephrotoxic to birds, has become a widely used veterinary medicine and was identi? ed as the cause ofthe decline; toxicity testing ofdiclofenac in four species ofGyps vulture caused dose-dependent mortality (LDSU of0.225 mg kg" vulture body weight) and identical clinical signs (visceral gout) to those found in carcasses ofwild birds. In carcass dumps, detectable diclofenac in l0. l% of 1848 domestic ungulate carcasses was noticed which was' the important and sole cause of vulture population decline. Others causes like food availabilityj loss ofbreeding 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.