Dog, squirrel deaths prompt new West Nile worries
Date: 20-Sep-02
Country: USA
While most of the attention has been given to the toll on
human health taken by the mosquito-born virus - 71 confirmed
deaths nationwide and more than 1,500 cases of infection -
the virus has wiped out colonies of birds and killed or
sickened hundreds of horses.
The College of Veterinary Medicine at the University of
Illinois said an 8-year-old dog, an Irish setter-golden
retriever mix, died of a West Nile viral infection, the
first such canine death reported in the country. It also
said a young wolf kept at a zoo died of the same infection.
The American Veterinary Medical Association could not
confirm it was the first dog death but other experts keeping
track of animal infections had previously not reported one.
The Illinois school said the dog may have had another
immune-compromising infection, as did three squirrels whose
deaths were also believed to be the first in the country
attributed to the virus.
"I think our squirrel population is going to take a hit. At
this point ... we don't see an unusual risk for the spread
of the West Nile virus from squirrels or dogs to humans,"
said John Andrews, director of the college's Veterinary
Diagnostics Laboratory.
"We believe the highest risk to humans is from mosquitoes,
but precautions should be taken around squirrels that might
be acting funny and with dogs whose health may be
compromised by other immune-related diseases," he added.
People who find dead squirrels should dispose of them, he
said, but if someone sees a squirrel exhibiting nervous,
disease-like behavior and then it dies, state wildlife
officials should be told, he said.
He said dog owners may want to limit the exposure of their
pets to mosquitoes, especially if the dogs are already
suffering from other diseases.
The West Nile virus is widespread throughout Asia and
Africa, and first was reported in the United States in 1999,
when an outbreak of the virus killed seven people in New
York.
It has since spread to nearly every state in the continental
United States.
Mosquitoes contract West Nile from infected birds and then
spread it to humans. The only person-to-person spread of the
disease that has been reported came through transplanted
organs. It cannot be spread directly from birds to humans.
Andrews said researchers doubt that infected squirrels
develop sufficiently high concentrations of the virus in
their bloodstreams to transmit it back to either mosquitoes
or humans, though the matter is still under investigation.
Most people who become infected suffer no symptoms and those
who do have only headaches and flu-like illness. But the
elderly, chronically ill and those with weak immune systems
can develop a possibly fatal encephalitis.
