Veterinary diclofenac threatening EU bird of prey population

European vulture and eagle populations are being decimated needlessly as a result of the continued use of a harmful pain relief drug for livestock, argue Catherine Bearder and Steve Zack.

It is hoped the European Union will soon consider action against a veterinary drug that kills vultures and eagles and has led to a dramatic decline in their populations. The drug, diclofenac, was responsible for one of the greatest environmental crises of the past 50 years. Yet shockingly, its use is still currently authorised within a small number of member states, including Spain and Italy, despite the availability of a safe alternative.

Administered to livestock as an anti-inflammatory and to relieve pain, diclofenac can cause renal failure when ingested by birds of prey feeding on the carcasses of animals treated with the drug. Carcasses from fallen animals are rare in northern Europe, but in many parts of southern Europe cattle, sheep and pigs are free range, meaning that birds of prey can find them long before farmers do if they die. As specialised scavengers, vultures are especially vulnerable. Eagles, which likewise consume carcasses, are also at risk.

"The effects of [diclofenac] can be disastrous. Between 1990 and 2003, more than 95 per cent of vultures in the Indian subcontinent disappeared"

The effects of the drug can be disastrous. Between 1990 and 2003, more than 95 per cent of vultures in the Indian subcontinent disappeared. It was not known originally that veterinary diclofenac was responsible for the great increase in bird mortality. Considerable scientific investigations were required to make that connection. Yet we now know that diclofenac breaks down very slowly in cattle and pigs and that only a small proportion of contaminated carcasses are required to cause massive declines in vulture populations. As a result India, Pakistan, Bangladesh and Nepal subsequently banned the substance.

Inexplicably though, diclofenac continues to be used legally in some EU member states. This is particularly perplexing given that an alternative drug, meloxicam, has been discovered which has similar veterinary properties while remaining safe for vultures and other birds of prey. The discovery came almost too late for several species of vulture on the Indian subcontinent. The devastation to certain populations, including the white-rumped vulture - then the most-abundant bird of prey in the world - leaves it very unclear if and how soon they can recover. Yet it is not yet too late for birds of prey in the EU.

In Europe, three vulture species are currently threatened. The Egyptian vulture, found in EU countries including Spain, Italy and Greece, is already recognised as "endangered" by the international union for the conservation of nature. Meanwhile the cinereous vulture and the bearded vulture are currently listed as "near threatened". Another species, the griffon vulture, has recovered from very low population levels due to intensive conservation efforts.

Due to their international importance for conservation, these vultures are listed on the EU birds directive as species requiring special conservation measures to ensure their survival. The EU has therefore invested considerable time, effort, and funding to protect them. Sadly, however, these birds of prey now find themselves at risk from even low exposure to veterinary diclofenac. Equally troubling, iconic eagle species such as the golden and imperial eagle are also vulnerable.

Several NGOs and MEPs from a range of political groups have expressed their concern on this issue to the European commission. The EU's European medicines agency - specifically the committee for medicinal products for veterinary use - is due to announce its opinion on the use of diclofenac on 11 December. That opinion will then be considered by the commission.

We hope that the commission learns from the terrible consequences of veterinary diclofenac use in the Indian subcontinent and bans its use in Europe now. Such an outcome would protect vultures and other vulnerable species from a reckless and entirely avoidable fate. The catastrophic decline of vultures on the Indian subcontinent was inadvertent. To allow it to occur again in Europe would be unforgivable.