Rabies tragedy follows loss of India's vultures

Date: Tue 12 Aug 2008
Source: New Scientist, magazine issue 2668 [edited]
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http://www.newscientist.com/article/mg19926684.400-rabies-tragedy-follows-loss-of-indias-vultures.html
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Rabies tragedy follows loss of India's vultures
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A conservation catastrophe has become a human tragedy. The mass
poisoning that has killed millions of India's vultures may have
indirectly claimed the lives of almost 50 000 people, according to an
analysis of the wider impacts of the bird die-off.

Since the 1990s, numbers of long-billed, slender-billed and oriental
white-backed vultures have declined at an unprecedented rate. All 3
species could be driven toward extinction within a decade. The cause
is a veterinary drug called diclofenac, which was routinely given to
cattle. When the cattle died, vultures that fed on their carcasses
were poisoned by the drug. Although now banned in India, diclofenac
is stlll used to some extent.

It seems the drug has also had an unforeseen knock-on impact. As
vulture numbers crashed, the population of feral dogs across India
surged, feasting upon cattle carcasses that would otherwise have been
stripped bare by birds. Many of these dogs carry rabies, and now
scientists in the UK and India, led by Anil Markandya of the
University of Bath, UK, have put a figure on how many people have
died from rabies after being bitten by such dogs. "As the vultures
died, the population of rabid feral dogs across India surged,
feasting on uneaten cattle carcasses."

They calculate that the decline of vultures made way for at least 5.5
million extra feral dogs in India between 1992 and 2006. During this
[14-year] period, these extra dogs would have been responsible for at
least 38.5 million bites. National surveys show that in India 123
people die of rabies per 100 000 dog bites, suggesting that a minimum
of 47 300 people have died of rabies as a result of the vulture
die-off. Taking account of the cost of treating bite victims and
dealing with the extra deaths, the researchers calculate that the use
of diclofenac has indirectly cost India USD 34 billion.

Despite the scale of the disaster, "it is unfair to blame anyone, as
the impacts of diclofenac were unforeseen," says Markandya. "The
lesson is to check the consequences of drugs before using them for
animals that are part of an ecological system such as this." [How? -
Mod.JW]

[Byline: Matt Walker]