Epizootic hemorrhagic disease. cervids - USA (TX)(02)

International Society for Infectious Diseases
<http://www.isid.org>

[1]
Source: San Angelo Standard Times [edited]
< http://www.sanangelostandardtimes.com/sast/news_local/article/0,1897,SAST_4956_4998221,00.html>

Disease killing area deer; possible outbreak linked to deaths
-----------------------------------------------
High numbers of dead deer found by landowners in Schleicher and
Sutton counties have alerted Texas Cooperative Extension wildlife
experts about a possible outbreak of a viral disease. ''While some
level of deer mortality is not newsworthy, it looks like there could
be a hotspot developing for epizootic hemorrhagic disease,'' said Dr.
Dale Rollins, Extension wildlife specialist at San Angelo.
''Epizootic hemorrhagic disease is a viral disease very similar to
bluetongue in sheep and cattle, but ... tends to be most common in
white-tailed deer.'' At the same time, he noted, deer dying from
epizootic hemorrhagic disease are expected, but it's impossible to
predict where deaths will happen from year to year.

Corey Stevens, Schleicher County Extension agent, said he has seen a
lot of dead deer, primarily in July and August 2006, but he
attributes the deaths to starvation because of the drought. ''The
dead deer I've seen were real thin and appeared to be trying to use
all their strength to get to water,'' said Stevens, of Eldorado,
about 45 miles south of San Angelo.

''When we see an abnormal number of dead deer in August and
September, and the mortalities are near water holes, epizootic
hemorrhagic disease is often the culprit,'' Rollins said.

Although Dr. William Edmiston's Eldorado veterinary office has
recorded no cases, Rollins said most of the calls he received came
from Schleicher County landowners who have found dead deer at water
sources, dirt tanks and livestock water troughs.

The disease (Washington State Department of Fish and Wildlife):

Epizootic hemorrhagic disease is common in white-tailed deer and
rarely affects other species. It occurs in the driest part of the
year when conditions are just right for biting gnats, the carriers of
the disease.

The disease is not contagious from one animal to another, and it is
not transferable to humans. It comes from a virus carried by biting
gnats that live in or near water and wet, muddy areas. It is
transmitted to deer that congregate at such watering holes during
warm, dry weather.

The spread of the disease is usually cut short with colder, wetter
weather that spreads deer out and away from gnat-infested areas or
the 1st hard frost, which kills the disease-carrying gnats. Because
the incubation period for the disease is 5 to 10 days, afflicted deer
might be observed up to a couple of weeks after frost.

Deer in the early stages of EHD might appear lethargic, disoriented,
lame or unresponsive to humans. As the disease progresses, the deer
might have bloody discharge from the nose, lesions or sores on the
mouth and swollen, blue tongues. They become emaciated because they
stop eating. Sometimes they even stop drinking, although many die in
or close to water.

Domestic livestock could also be exposed, although cattle and sheep
are usually only carriers, not victims, of the ''bluetongue'' virus,
which is similar to EHD.

Because deer hunting season usually doesn't open until after the 1st
killing frost, deer hunters usually don't see live, infected animals.
Still, it is advisable to avoid shooting and consuming deer that show
any EHD symptoms, even though the disease cannot be transmitted to humans.

[Byline: Jerry Lackey]

******
[2]
Source: Star-Telegram.com [edited]
<http://www.dfw.com/mld/dfw/news/state/15535438.htm >


A team of wildlife specialists and animal disease experts,
coordinated by the Parks and Wildlife Department, is scheduled to
begin work in the area next week [this week] to investigate an
unusual number of deaths of white-tailed deer, all found dead or
dying near stock tanks or other water sources. The deaths -- which
come as hunters prepare for deer season -- are believed to be caused
by an ailment related to bluetongue disease, known clinically as
epizootic hemorrhagic disease, which cannot be passed to humans,
according to animal scientists and the Texas Department of Parks and Wildlife.

Officials said there is no immediate cause for public health concern.
But they said they have not ruled out anthrax, which can be
transmitted to people, as a cause for the deaths in a 6-county area
south of San Angelo. "We don't know. ... Anthrax is not out of the
question," said Dale Rollins, a wildlife specialist for the Texas
Cooperative Extension Service in San Angelo. [Last summer 2005, there
was a bad epizootic of anthrax in the Sutton county area.]

The drought has weakened the immune systems of deer and other
wildlife, and a recent spate of rains has helped spawn a biting,
virus-spreading fly, the culicoides [sic, a midge, not a fly]. So
it's more likely that the deaths are from epizootic hemorrhagic
disease, or EHD, officials said. "There's a lot more indication that
it's bluetongue or EHD simply because we're not seeing the mortality
in other creatures," said Clayton Wolf, the Parks and Wildlife
Department's big-game director.

Reports of unexplained deer deaths began coming in several weeks ago,
centered in Schleicher County and the surrounding ranchland counties
of Concho, Tom Green, Menard, Crockett and Sutton. The number of
deaths is unknown, but one report totaled 2 dozen dead deer on one
ranch. Another rancher reported finding 15 deer, both male and
female, dead and submerged in his stock pond. [The investigation team
is] "going to actually try to find freshly dead deer, or (living)
deer in poor condition, and try to perform (autopsies) [sic,
necropsies] to get to the bottom of this," said Mitch Lockwood,
director of the department's white-tailed-deer program.

Residents in the deer-hunting parts of Texas are reluctant to talk
about a disease outbreak because it could discourage hunting, an
extra source of income for the 6 counties. But officials said a cause
for the deaths should be determined before archery hunting of deer
begins on 30 Sep 2006. Gun season begins on 4 Nov 2006. Even if a
hunter bags an infected deer, Lockwood said, "there's no concerns
with humans consuming meat from a deer that has EHD."

[Byline: Jack Douglas]

We have had parallel reports of deer die-offs in Jim Hogg County in
South Texas, so this problem is probably much more widespread than
this report indicates. Also, I am suspicious that the recent axis
deer death in Uvalde County that was laboratory negative for anthrax
might have been EHD. Because of the history of anthrax in west and
south Texas and its gross similarity to EHD, many Texas deer ranchers
are most reluctant to send samples to TxVMDL for laboratory
confirmation. In this present series, it seems that only one deer was
necropsied in West Texas but without sample submission. With the
present rain pattern in the region, the investigative team may be
lucky and find a recent case. The turkey buzzards/vultures are very
efficient, and if you are not very quick on your feet, all one will
find is an eviscerated carcass. On the other hand, if they have been
feeding to capacity, they get picky and ignore carcasses and then
search out their individual preferences, e.g., rattlesnakes.