Experimental safety testing confirms that the NSAID nimesulide is toxic to Gyps vultures in India

Abstract

Population declines of Gyps vultures throughout South Asia were caused by unintentional poisoning by the NSAID diclofenac, which was subsequently banned. However, other vulture-toxic NSAIDs are available, including nimesulide, which, in experiments carried out in South Africa, was shown to be toxic to Gyps vultures. We report on safety-testing of nimesulide carried out on Himalayan Griffons G. himalayensis. We gave two vultures a dose of nimesulide by oral gavage at the maximum level of exposure, with two controls dosed with benzyl alcohol. In the two tested birds, plasma nimesulide concentrations peaked after six hours, while serum uric acid concentrations increased steadily up until 24 hours post-treatment, after which both birds died, displaying severe visceral gout. The control birds showed no adverse clinical or biochemical signs. We confirm that nimesulide is toxic to Gyps vultures. Veterinary use of nimesulide should be banned in all Gyps vulture range countries in the region.