Diclofenac: A Drug that Killed Vultures in India and Now Europe?
A drug that is known to be responsible for critically endangering Indian vultures has been approved for use in the EU, with conservationists saying this reckless move seriously undermines efforts to protect birds of prey like Scotland’s eagles.
The drug, called veterinary diclofenac, is an anti-inflammatory and was given to India’s livestock as a means to help fend off a number of diseases that result from intensive cattle rearing. No one thought much of it until the numbers of Oriental white-backed vulture, a species that in the 1980s was so abundant it was one of the most common large birds of prey in India, started falling dramatically.
The birds were often found dead next to the carcasses of livestock and it didn’t take too long before researchers began to find a link. The birds were consuming meat from animals that had recently been treated with diclofenac. Through eating that meat, the vultures were also being exposed to the drug which quickly attacked and shut down their kidney function, leading to a rapid death. While it was estimated that only 1% of cattle might have carried a lethal dose, this alone was enough to destroy the vulture population by, some estimates suggest, a staggering 61%.
India banned the drug for livestock use in 2006. Administrations in Nepal and Pakistan quickly followed, and the effect was marked. Since that time, studies have shown that the bird’s numbers have recovered by about 55%, though whether they will ever reach the numbers they once had is unknown. There is some doubt because the drug is still found in some animal carcasses today as a result of illicit sales of the drug and also through legal means of obtaining it as part of other drugs. Conservationists remain concerned that diclofenac still poses a real danger.
As a result, when earlier this year the EU licensed diclofenac for livestock use in Italy and Spain, conservationists were very alarmed. Spain in particular is a stronghold for the majority of several of Europe’s vulture populations, and evidence shows it takes very little exposure to diclofenac to have an impact. The problem doesn’t stop there either, because now the drug is available as part of a wider treatment called Reuflogin that treatment can be transported throughout the EU without much restriction and has already broken into the markets in Latvia and Turkey.
It’s especially infuriating given that there’s scientific research to support that diclofenac is still killing birds in India and abroad even today.
A study, published this month in the journal Bird Conservation International, saw researchers present the findings of postmortem tests carried out on two steppe eagles, which are the cousins of Scotland’s gold eagles. The birds were found dead at a cattle carcass dump in Rajasthan, India. Despite the ban on diclofenac, the birds were found to have the same lethal doses of the drug in their systems and the resulting kidney failure. This, the researchers say, could mean that all of the eagles’ cousins, with around 14 species spread throughout Europe, may reasonably be said to be in danger from the drug. Add this to what we know about vultures and that means that many more birds of prey which feed on livestock meat could be at risk.
Another study published in April in Bird Conservation International didn’t show a direct link to diclofenac but did find that two other vulture species in both India and Egypt and their population declines appear to tally with observations of rising diclofenac traces. That’s not concrete evidence, but given what we know of diclofenac, it does at least present cause for concern.
So why did Europe allow the use of diclofenac? The drug is relatively cheap (compared to its main substitute meloxicam). However, there probably is some science denial going on here too. There are a small minority of researchers who contend that diclofenac isn’t as lethal as has been suggested and instead that the vultures and other large birds of prey are being killed by a virus. As the Guardian notes, evidence for the virus theory is spare, especially when compared to other possible factors like pesticides, yet grants are still being given out to examine this line of inquiry — of course that’s not necessarily bad, but when it detracts from what the science does say about diclofenac’s role, that is damaging.
The UK is at least taking the threat of diclofenac seriously, with the UK’s Veterinary Medicines Directorate releasing a statement saying: “As a precautionary measure the VMD will not approve any requests from vets to import products containing diclofenac. Furthermore, the VMD has agreed not to issue any export certificates which name diclofenac-containing products in the list of products to be exported.”
In the meantime, conservationists continue to push for an EU-wide ban on the drug to ensure that what happened to India’s vulture populations doesn’t also happen within Europe’s borders.
Photo credit: Thinkstock.