A paper published in the current issue of Science of the Total Environment confirms that the non-steroidal anti-inflammatory drug (NSAID) nimesulide is toxic to vultures, following safety testing of the drug on vultures in South Africa.

Since the banning of veterinary diclofenac, the NSAID which drove three species of Gyps vultures to near-extinction in South Asia, there has been an urgent need to test other NSAIDs also available on the market for veterinary use, and which are suspected to also be toxic to vultures. One such drug which is becoming increasingly popular especially in India was nimesulide.

White-rumped vulture have already experience a devastating population crash due to one NSAID (c) Paul Insua-Cao (rspb-images.com)

The drug was already implicated in the deaths of several vultures in NW India, which showed signs of NSAID poisoning, i.e. visceral gout, coupled with nimesulide residues in the blood. Now, these published results  confirm that nimesulide is, indeed, highly toxic to vultures.

In a safety testing experiment carried out in South Africa, in which two Cape griffon vultures (Gyps coprotheres) were given nimesulide, both birds developed increased concentrations of uric acid in the blood and visceral gout, symptoms of kidney failure, and as with diclofenac poisoning, they died within two days of dosing. Double the recommended dose was given to the birds to replicate the common practice in India, where farmers regularly give such large doses of drugs to their injured cattle. Safety testing has been widely conducted to test the toxicity of drugs to birds, and was instrumental in proving the toxicity of diclofenac, which led to its subsequent ban.

To avoid too many birds being exposed to a potentially harmful drug, only two birds are given a dose of a drug in the initial phase of the experiment, and if at least one of these birds die then the experiment is stopped and the drug declared toxic. Both birds in this latest experiment were residents of the VulPro Rehabilitation Centre, located outside Pretoria, South Africa, due to injuries that prevented them from ever being released.

The results of this study are incredibly important, confirming what we have suspected for a number of years, that nimesulide can kill vultures.

The government of India previously acted quickly to ban diclofenac, which prevented vultures from going extinct. Now that there is evidence of nimesulide’s toxicity, SAVE are calling upon the Government of India to take urgent steps to ban this drug for veterinary use, to support the ongoing recovery of vulture populations in India and elsewhere in South Asia.

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