Thursday, December 10, 2009

New Trouble for Asian Vultures

During the past decade, several Asian vulture species lost most of their populations due to the harmful effects of diclofenac, a veterinary drug. Some species declined by as much as 90%. That drug has since been removed from the market. Unfortunately, one replacement, ketoprofen, is not an improvement since it causes birds to die of kidney failure.
The research, published in the Royal Society journal Biology Letters, shows that ketoprofen is lethal to the birds in the dosages that would be administered to livestock to reduce pain and swelling of those animals suffering from rheumatism or arthritis. Worryingly, researchers have already recorded the drug in one in 200 carcasses in southern Asia, with 70% of those occurring in potentially lethal concentrations.

The authors add that ketoprofen could already be contributing to further declines of the remaining vulture populations caused by diclofenac, and this is a trend likely to increase if ketoprofen replaces diclofenac. In addition to ketoprofen and diclofenac, other non-steroidal anti-inflammatory drugs sold by veterinary pharmacies for treating livestock include meloxicam, phenylbutazone, analgin, nimesulide, flunixin and ibuprofen. Just three of these have been tested to determine their effects on vultures. Diclofenac and ketoprofen cause lethal kidney failure and only meloxicam is known to be safe.
Meloxicam is known to be safe for vultures and is not covered by a patent, so it ought to be the top choice as an alternative to diclofenac. As one of the biologists said, it would be helpful to have more medication options available, but they really need to be tested in advance. With several species in such a precarious state, there is little room for error.