Decline in vulture population is the first major case of ecological damage
First major case of ecological damage caused by pharmaceutical product.Diclofenac used in India because it is cheap Fatal effect on vultures feeding on carcass
JAIPUR: The official ban on diclofenac, an anti-inflammatory drug used to treat cattle in India, has come not a day too soon considering the devastation it caused to the vulture population in the subcontinent. Even two years ago it was ascertained that the steep decline in the population of Gyps vultures in India, Pakistan and Nepal could be directly attributed to the use of the drug. Vultures, which consumed the carcass of animals treated with diclofenac, died with symptoms of kidney failure.
The May 11 order on phasing out the drug, issued by Ashwini Kumar, Drugs Controller-General, said: "Extensive studies have indicated that the use of diclofenac in livestock is the major cause of vulture decline."
The decline, especially of the population of White-backed vultures (Gyps bengalensis), was first noticed in the early 1990s in the Keoladeo Ghana National Park area of Bharatpur in Rajasthan. Vibhu Prakash, principal scientist with the Bombay Natural History Society, on an assignment on raptors, reported it first and alarm bells rang the world over.
"The number of White-backed vultures has come down to a few hundreds. Their nests, often found on trees, are a rare sight in north India while the Long-billed vultures, which build nests on cliffs, have seemingly survived the onslaught of the killer drug," says Harsh Vardhan, an environmentalist who launched a "Save vulture" campaign.
After long search, a team of 13 scientists, led by J. Lindsay Oaks, assistant professor of veterinary medicine at Washington State University, zeroed in on diclofenac. A non-steroidal anti-inflammatory drug of the kind of ibuprofen, diclofenac is prescribed for patients with arthritis in the United States. In India, the drug is widely given to cattle because it is cheap and helps to prevent afflictions including lameness and fever.
The decline in the vulture population is said to be the first major case of ecological damage caused by a pharmaceutical product. Unlike DDT, which too devastated the population of birds of prey in the past, diclofenac does not accumulate in the tissues of livestock or birds. The findings came as a surprise as till then the suspected culprits were environmental toxins.
Mr. Vardhan said that in India "authorities initially were not even willing to concede that there was any threat to the vulture population. And when it came to looking for the causes of sudden deaths, the country refused to let the tissues of the dead vultures taken out for pathological examination."
However, experts from the U.S., the United Kingdom and other countries got together to solve the riddle. The Idhao-based Peregrine Society tied up with the Ornithology Society of Pakistan for the cause. The tests, which led to the findings on diclofenac, were done with autopsies on vultures received from Pakistan.
The battle is not over for the Gyps vultures. Though the government order talks about an alternative medicine Meloxicam, it is for the State Governments to strictly implement the ban on the manufacture and use of diclofenac. Help In Suffering, a voluntary body, discontinued the use of diclofenac in the treatment of stray cattle it picks up in the Pink City.