Indian vultures, especially White-backed, Long-billed and Slender-billed, are exposed to Diclofenac, a Non-Steroidal Anti-inflammatory Drug (NSAID), when they consume carcasses of cattle that were administered this drug.
Though Diclofenac was banned for veterinary purpose in May 2006, government in August 2008 permitted the production of `human diclofenac`.
C Sasikumar, Ornithologist of Malabar Natural History Society, said lack of awareness about the ban means it continues to be recommended by veterinarians and used by cattle owners.
Diclofenac is used widely as a painkiller in livestock practices in the country.
Sasikumar, who is part of a team conducting a survey to check the prevalence of NSAIDs among livestock in Tamil Nadu, Karnataka and Kerala, said the drug was still freely available packaged in 30 mls vials.
"This is a very dangerous situation as far as vultures are concerned and if not controlled immediately, the remaining population also will be extinct in the near future", he said.
Supporting Sasikumar`s view, G Christopher, who is the Research Coodinator of School of Environmental Sciences at Mahatma Gandhi University in Kerala, said vulture population had decreased from at least 100 vultures per square km in North India and 50 to 60 per square km in South India.
Less than a per cent of the livestock carcasses available to vultures need to contain diclofenac to prove lethal to vultures, he said.
But a 2006 a Bombay Natural History Society (BNHS) survey revealed that 11.1 per cent of the livestock carcasses in India were contaminated with diclofenac, which led to the ban on the drug being imposed by the government, he said.
With respect to the survey, which was initiated by BNHS, in association with the local conservation groups, Christopher said as in other parts of the country, most of the vulture population in the Tamil Nadu, Karnataka and Kerala has also been decimated since the 1990s.
Only a small population of vultures still existed in the continuous forest stretch of Mudumalai and Sathyamangalam in Tamil Nadu, Bandipur and Nagarhole in Karnataka and Wayanad in Kerala, Sasikumar said.
Asked about conservation of vultures, Christoper said steps are being taken to increase the population by captive breeding in sanctuaries in Pinjore in Haryana, Buxar in West Bengal and Guwahati in Assam. Measures are also being taken to begin such captive breeding in South India, he said.