Proscribed drug poses a threat to vulture population

The illegal use of diclofenac for veterinary purpose is posing a threat to the vulture population in the country despite a ban on its veterinary use since 2006.

Recent studies showed that it is available in a number of pharmacies.

The drug was banned after its traces were found in cattle carcasses. The drug proved fatal for vultures feeding on the carcasses, resulting in a sharp decline in their population.

Use of vials

A study, jointly carried out by the Bombay Natural History Society, the Royal Society for the Protection of Birds and the Critical Ecosystem Partnership Fund on the availability of the drug across 11 States from November 2007 to June 2010, revealed that the 30ml vials meant for human use were purchased over the counter at many places and used for veterinary purposes.

The survey, covered over 250 veterinary and general pharmacies.

The “veterinary use of diclofenac, a non-steroidal anti-inflammatory drug, is the main factor responsible for the decline of the species of Gyps vultures in South Asia.

Studies have established that diclofenac is toxic to vultures and is widespread in cattle carcasses across India at sufficient concentrations to be the principal cause of the decline,” the report said.

In Kerala, diclofenac was sold in a couple of pharmacies in Attapadi and Thiruvananthapuram, said C. ornithologist Sashikumar, who led the study in Kerala.

The team, consisting of K. Vishnav and P.A. Vinayan, covered 39 medical shops in Wayanad, 25 in rural area of Thiruvananthapuram adjoining Tamil Nadu and 15 in Attapadi.

Though none of the shops surveyed in Wayanad was found selling the 30ml vials, they were available in pharmacies in Gundalpet and Masanagudi, which were close to vulture habitats of Mudumalai and Bandipur Tiger Reserves.

“The vultures foray around 200 km in search of food and there exists the possibility of them feeding on carcass of cattle which were treated with the drug,” Mr. Sashikumar said.

Traces of the drug would remain in the body of the animal for around 48 hours of use and could be lethal for birds feeding on the carcass.

During the survey, it was also found that some pharmacies were selling diclofenac for human use in large volumes for multiple dosages, which could also be used for veterinary purpose.

The study recommended the reduction of size of vials of the drug meant for human use and action against pharmaceutical manufacturers and pharmacies flouting the ban.

In Kerala, two species of vultures — Oriental White-backed and Red-headed Vultures — are found in Tholpetty, Bathery and Kurichiyat forest ranges of Wayanad Wildlife Sanctuary.

Ornithologists are of the view that there would be around 20 nesting pairs of the White-backed vultures in Wayanad. No incidents of bird death were reported from the area.

There were reports of sighting of vultures in Periyar and Parambikulam areas in the 1980s. However, the vulture population was now confined to Wayanad, Mr. Sashikumar said.