A paper by Pradeep Sharma from Rajasthan University of Veterinary and Animal Science, Bikaner, published in the Journal of Raptor Research, claims that aceclofenac metabolises into diclofenac.
"A study demonstrating in vivo conversion of aceclofenac into diclofenac in cattle will be important. Once proven this will establish the exposure of vultures to diclofenac," Sharma said.
The use of diclofenac on livestock is already banned in India because it causes death of vultures, which feed on the carcasses of animals to survive.
The population of white-backed, long-billed and slender-billed species of vultures has suffered a catastrophic decline of about 99 per cent over the past decade.
The International Union for the Conservation of Nature (IUCN) has classified them as critically-endangered.
Vultures, which are scavengers, are crucial in the ecological cycle. With their robust digestive system they eat disease-causing pathogens in rotting meat of dead animals which helps in preventing outbreak of infectious diseases such as anthrax and rabies.
More From This Section
The aceclofenac issue also points to the need for a comprehensive environmental evaluation of veterinary drugs before granting licenses, Sharma said.
Commenting on the report, eminent ornithologist and director of the Bombay Natural History Society (BNHS) Dr Asad Rahmani said, "In order to create a safe natural environment for vultures in south Asia, banning unsafe drugs and safety testing of other potentially toxic drugs should be a priority."
To ensure long-term survival of vultures, safety testing of all veterinary painkillers was necessary to prevent use of other unsafe drugs such as ketoprofen, he said.