Subject: coot disease
Date: Feb 12 14:59:50 1998
From: "J. Marrazzo" - jmm2 at u.washington.edu


Given the abundance of our coot population, I found this article
interesting--particularly regarding potential for spread of this avian
parasite, which is unknown. I assume that the Seattle coot population
is largely west-coast based and wouldn't usually come in contact with
this focus of potential infection, but I may be wrong....interesting...

Jeanne Marrazzo

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PARISITISM, AVIAN, FATAL - USA (WISCONSIN)
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A ProMED-mail post

NEW PARASITE KILLS BIRDS ON WISCONSIN LAKE [edited]

Madison, WI - Dr. Rebecca Cole, a parasitologist at the U.S. Geological
Survey's National Wildlife Health Center in Madison, Wisconsin, has
reported that _Leyogonimus polyoon_ was responsible for killing large
numbers of waterbirds in Shawano Lake, Wisconsin, last fall. In just two
months last fall, more than 12,000 coots and dabbling ducks died at Shawano
Lake; 1,400 died there the year before.

Cole identified the exotic parasite, _Leyogonimus polyoon_, in the
carcasses of nine coots collected this year from the 6,000-acre Shawano
Lake. Cole said that although the parasite was not detected during the 1996
die-off, she was able to find it in preserved samples from that event as
well. _Leyogonimus polyoon_ now shares responsibility for the Shawano Lake
die-off with _Sphaeridiotrema globulus_, a trematode parasite previously
linked to the waterfowl deaths.

_Leyogonimus polyoon_ is a common killer of moorhens and coots in Eastern
Europe, especially in the Danube River area. The [intermediate stage of
the] parasite resides in snails, which are an important food source for
moorhens and coots alike. Once inside a bird's body, the parasite causes
intestinal damage and a slow death.

Cole does not know which of the many varieties of snail in Shawano Lake
carries the parasite. Also unknown is how easily the parasite can spread.
Many coots migrate to Florida and other Southern states for the winter. The
coot migration may enable the parasite to spread to other regions of the
country.

So far, wildlife managers in the area have not reported any other events
similar to the die-off in Shawano Lake. "We hope something peculiar about
Shawano Lake not only allowed it (_L. polyoon_) to occur there, but will
also keep it there," said Cole. She has only found the new parasite in coot
carcasses. She does not know if other snail-eating birds are at risk. They
may not be susceptible to the parasite, or they may not feed on the
infected snail species.

According to Cole "There are many unanswered questions about the parasite,
the snail vector, and the potential of this parasite to spread. More
research into the Shawano Lake die-offs may yield further information on
the parasite's life cycle and the threat it poses to wildlife."

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