After Diclofenac-like painkillers, nimesulide drug is becoming a major scourge for white-rumped vultures in the country, threatening to wipe out the critically endangered birds which are categorised under Schedule I of Indian Wildlife Protection Act 1972.

Researchers have now sought a ban on the use of nimesulide for veterinary purposes. Like Diclofenac, nimesulide is used to lessen pain in animals and humans.

The  volume of human formulations should also be regulated to avoid misuse, they said after concluding that  nimesulide was responsible for the death of four white-rumped vultures in two separate incidents in Gujarat during 2019. They were found dead below a roosting site in Sanand. Two others were found dead below a roosting site in the Wild Ass Sanctuary, Dhrangadhra in the State.

In their study published in the international scientific journal, Environmental Science and Pollution Research, the researchers said that after post-mortem examination, a thorough scientific viscera analysis was conducted at the National Centre for Avian Ecotoxicology at the Sálim Ali Centre for Ornithology and Natural History, Coimbatore, on the organs, including kidney, liver, intestine and gut contents, of the dead birds.

It was found that all the white-rumped vultures were exposed to nimesulide through carcasses of cattle they consumed before death. “Uric acid deposits, as crystals or powder, were observed in the internal organs of all four vultures although the intensity was different,” said the team of Kanthan Nambirajan, Subramanian Muralidharan, Aditya Roy Ashim Kumar, all from Division of Ecotoxicology, SACON, and Shashikant Jadhav from Jivdaya Charitable Trust, Ahmedabad.

“Therefore it could be concluded that uric acid deposition observed in the viscera in all the four vultures during post-mortem and elevated levels of nimesulide residues in the organs and gut content was responsible for the mortality of all the white-rumped vultures in Gujarat during 2019,” they said.

The population of the white-rumped vulture in India as of 2015 was about 6,000. Despite efforts, the population of the species is yet to reach a healthy level. Moreover, while mortality of white-rumped vultures due to diclofenac continued to be reported in India, poisoning also made its contribution.

Ban on the use of diclofenac for veterinary use in India as early as 2006, and the reduction in volume of diclofenac formulation for human use to restrict misuse for veterinary purpose in 2015, has slowed down the population decline of white-rumped vulture. But the population is still at low levels (5729) in India unlike Nepal and Pakistan where the population recovered subsequent to the ban on diclofenac, said the study.