- A study of four white-rumped vultures, found dead in Gujarat in 2019, showed that vultures were exposed to the veterinary drug nimesulide, through the carcasses of cattle they ate.
- According to the study, nimesulide appears to work the same way as another drug, diclofenac, exerting toxic effects on vultures. The government-funded study called for its ban.
- Diclofenac is one of the main reasons for the eradication of 99% of the vulture population in India in the 1990s. Despite the ban, diclofenac is still used in veterinary medicine in India.
A veterinary pain reliever, nimesulide, has caused the death of vultures in India, according to a new study published in the latest edition of the international scientific journal, Environmental science and pollution research.
Diclofenac has long been established as the main reason for the eradication of 99% of the vulture population in India in the 1990s. Later, two other veterinary drugs – aceclofenac and ketoprofen – were found to be toxic to them. vultures. While diclofenac is banned, a proposal to ban the other two drugs is already under consideration by the Indian government, senior vulture scientist and deputy director of the Bombay Natural History Society, Vibhu Prakash told Mongabay-India.
According to the new study, nimesulide appears to work similarly to diclofenac by exerting toxic effects on vultures.
If the veterinary use of nimesulide continues, vultures could still suffer in India. Therefore, the study recommends that nimesulide be banned by the Indian government to conserve vultures in the Indian subcontinent.
The study is part of a government-funded project titled, National Center for Surveillance and Monitoring of the Impact of Environmental Contaminants on Ecosystem Components with a Special Focus on Birds in India. It was written by experts from the Division of Ecotoxicology, the Salim Ali Center for Ornithology and Natural History (SACON) and the Jivdaya Charitable Trust.
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Critically Endangered Ruminant Buffalo Vultures Study
The study was carried out on buffalo vultures (Gyps bengalensis), listed as Critically Endangered on the International Union for Conservation of Nature (IUCN) Red List since 2000 and listed in Schedule I of India’s Wildlife Protection Act 1972 for its safety and its conservation.
In two separate incidents in Gujarat in 2019, four white-rumped vultures were found dead – two found under a resting site in Sanand, while two others were found dead under a resting site in the donkey sanctuary savage, Dhrangadhra.
Gujarat forestry authorities located the dead vultures and Aditya Roy, one of the study’s co-authors, coordinated their transport to Ahmedabad. At the hospital, veterinarian Shashikant Jadhav, who is also a co-author of this study, performed the autopsy in both cases.
After a post-mortem examination, a thorough scientific analysis of the viscera was carried out at the SACON National Center for Avian Ecotoxicology in Coimbatore, on the organs, including the kidneys, liver, intestine and intestinal contents, of these dead birds.
The study concluded that all white-rumped vultures were exposed to nimesulide through cattle carcasses that they ate before dying.
He added that deposits of uric acid, in the form of crystals or powder, were observed in the internal organs of the four vultures although the intensity was different.
Therefore, it could be concluded that the uric acid deposits observed in the viscera of the four vultures during the autopsy and the high levels of nimesulide residues in the organs and intestinal contents were responsible for the mortality of all. white-rumped vultures in Gujarat in 2019, adds the study.
New findings pose new challenges for Indian policymakers
The Indian government has established eight vulture breeding centers and plans to establish eight more as part of the National Vulture Conservation Action Plan (2020-25). But there have been various studies that note that the Indian government has failed to control the use of toxic veterinary drugs for vultures.
In the 1980s and 1990s, most of the vulture populations disappeared from India. The vultures died after feeding on their staple diet – cattle carcasses – which contained high traces of diclofenac, a veterinary medicine.
Despite the ban in 2006, diclofenac still accounts for 10-46 percent of all pain relievers offered for sale for the treatment of livestock in India, suggesting weak enforcement of existing regulations. In addition, another legally available veterinary medicinal product, aceclofenac, is also rapidly metabolized to diclofenac after administration to livestock.
Now, verifying the use of another veterinary drug toxic to vultures, nimesulide, is another difficult task for policymakers and officials.
According to the study, nimesulide is widely available and used by vets in India, which increases the risk of vultures dying. The vulture population in India was around 40 million in the 1980s (belonging to three species – white-backed vulture, long-billed vulture, and slender-billed vulture). In 2017, it fell to 19,000.
The latest national vulture survey has been postponed twice, in March 2020 and March 2021, due to the COVID-19 pandemic.
Rhys Green, a professor at the University of Cambridge and chairman of Saving Asia’s Vultures from Extinction (SAVE), an international platform working for the conservation of vultures, which was not associated with the study, said in a statement that the new study provides convincing support if the authorization for the veterinary use of nimesulide should be withdrawn immediately.
Nimesulide was also found in the intestine, showing that the dead birds had recently fed on contaminated meat. Other drugs that cause the same problems, such as ketoprofen and aceclofenac, should also have their licenses withdrawn, Green said.
Chris Bowden, head of the SAVE program in India, said the decline in the vulture population has led to a massive increase in the wild dog population due to the easy availability of cattle carcasses. India has the highest incidence of rabies in the world and of the 20,000 rabies deaths each year, 96 percent are the result of dog bites. He said it is vital to rule out any possibility that is harmful to the vulture.
“The Indian government has done a great job in approving alternative drugs to diclofenac such as meloxicam which need to be widely promoted among veterinarians and livestock owners,” he added.
Bowden said the recent ban on veterinary ketoprofen by the government of Bangladesh earlier this year is a good example, and India is expected to replicate for veterinary products nimesulide, aceclofenac and ketoprofen as well as others. drugs for which safety is not yet established.
“Such measures are essential if the vultures are to have a future in Asia, and India has the greatest responsibility here,” he added.
Meanwhile, BNHS’s Vibhu Prakash, who works closely with the Indian government on vulture conservation, told Mongabay-India that Bareilly-based Indian Veterinary Research of India (IVRI) has already been given the task. to conduct safety testing of four other veterinary drugs, including nimesulide. The other three are ibuprofen, anlagen and paracetamol.
If it is established during safety tests that nimesulide is dangerous for vultures, there is a chance that it will be banned in India, he informed.
But according to Prakash, while the ban process will take its own course, there is a broader need to implement existing regulations to prevent the abuse of already banned drugs.
Here, the roles of the local drug controller and the inspector are important. They must ensure that pharmacists do not give out prohibited drugs without a prescription. “We did a little investigation in which we found that diclofenac was still given without a prescription even though it is currently scheduled as drug H, which cannot be given without a prescription,” he said.
The lack of trained vets and the overuse of killer drugs that leave a permanent trail of drugs inside livestock are other related issues, Prakash said.
“More than a ban, mass awareness is needed on the harmful impact on vultures, whose conservation is very important from an ecological point of view,” he said. “We are in the process of finding more drugs that are safer for vultures. One of these drugs, tolfenamic acid, will soon be recommended for veterinary use, which we believe is as effective as diclofenac, nimesulide and aceclofenac.
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Banner image: The white-rumped vultures that were studied in this research. Photo by Chris Bowden / SAVE.