“Another pneumonia outbreak has killed bighorn sheep in the Skalkaho area, and a veterinarian thinks smoke from wildfires may be to blame,” says an article in the Montana newspaper the Ravalli Republic. “If it spreads, the outbreak would be the 7th major die-off of bighorn sheep in western Montana since 2009.”
Read the rest of the story in the Ravalli Republic here.
Photo: A healthy bighorn sheep in Montana. Ryan Hagerty photo courtesy of US Fish and Wildlife Service.
“Another pneumonia outbreak has killed bighorn sheep in the Skalkaho area, and a veterinarian thinks smoke from wildfires may be to blame,” says an article in the Montana newspaper the Ravalli Republic. “If it spreads, the outbreak would be the 7th major die-off of bighorn sheep in western Montana since 2009.”
Read the rest of the story in the Ravalli Republic here.
Photo: A healthy bighorn sheep in Montana. Ryan Hagerty photo courtesy of US Fish and Wildlife Service.
Two white-tailed deer have been diagnosed with epizootic hemorrhagic disease (EHD) in a southwestern county of Michigan. Last year 250 deer in that Michigan county died of the disease.
A Michigan Department of Natural Resources press release has the details of the finding, plus a history of EHD in the state. The release states: “More frequent outbreaks of EHD in Michigan could be a consequence of climate changes that favor the northward spread of the biting flies that spread the disease, said Russ Mason, chief of the DNR Wildlife Division.”
EHD is endemic to North America. The disease is most common in white-tailed deer, but can infect all ruminants. Humans are not known to catch the disease.
Few deer die from the disease in the southeastern U.S., which experiences a mild form of the disease. Outbreaks in the Midwest and Northeast can range from a small outbreak with few deaths to something more widespread. The severity of the outbreak depends on the weather (wet weather favors breeding midges), how many of the biting midges are around, herd immunity, and other factors.
Previous research has shown that higher levels of biodiversity leads to lower levels of infectious disease because of the “dilution effect,” where some species are poor hosts of the disease or may not be infected at all, slowing disease transmission.
The dilution effect has been studied in Lyme disease and West Nile.
A paper recently published in the Proceedings of the National Academy of Sciences shows the dilution effect at work in chytrid fungus infections in Western toads. Other news outlets have reprinted the press release from Oregon State University. (We have a OSU two-fer this week. Go Beavers.)
Read the original release via EurakAlert.
The press release does not make clear that this was a laboratory experiment, or that the experiment was conducted with tadpoles. The Western toad tadpoles were raised in aquaria with American bullfrogs and Cascades frogs. You can read the Ph.D. dissertation that is the basis for the paper here. (It’s a big PDF, but that shouldn’t be a surprise.)
The laboratory setting with just three species (well, four, if you count the fungus) makes the conclusion that much more striking. It would be interesting to see how these findings hold up in the field.
Read the PNAS paper here (fee or subscription required).
Read a conference summary of the research from the Ecological Society of America annual meeting here.
Photo: Western toad. Courtesy Oregon State University.
One captive deer in Erie County, in the northwestern corner of the state, has also died of EHD, according to a Pennsylvania Game Commission press release.Photo: A healthy white-tailed deer. Credit: Ryan Hagerty, courtesy of US Fish and Wildlife Service
It is the season of biting midges, and therefore the season for epizootic hemorrhagic disease in deer.
In Kansas, there have been several reports of dead or dieing deer. Two of those cases have been confirmed as epizootic hemorrhagic disease (EHD), or EH, as this article in InfoZine that reported the outbreak calls it. Read the story here.
EHD is cited as the likely source of dead and dieing deer in Montana, in this article from the Liberty County Times.
Read the ProMed entries on both these events for background, wise commentary and corrections to the articles. The comments are at the bottom of the page in [brackets]. Read it here.
There is a possible outbreak in North Dakota. It is still being investigated. Read the story in the Bismark Tribune.
And finally, two weeks ago New Jersey announced a possible outbreak of EHD. We posted that as an addition to that week’s wildlife disease update, but in case you missed it, here’s the press release.
Late addition: On Sept. 7, 2011, New York State has announced that the death of 100 deer in Rockland County two weeks ago was caused by EHD. Read the press release here.
Photo: A healthy deer. Photo credit: Steve Hillebrand, courtesy US Fish and Wildlife
Dozens of white-tailed deer in Montana have died of a mysterious ailment which is suspected to be epizootic hemorrhagic disease. The Great Falls Tribune has a brief item. Check out this item on ProMed-mail for a helpful reference to the no-see-ums that transmit the disease.
[ADDITION: The day after this was posted, the state of New Jersey announced epizootic hemorrhagic disease in deer in that state. You can read the press release here.]
A feral hog in Midland County, Michigan has tested positive for pseudorabies. Read the article on Michigan Live, here. Sounds ridiculously scary until you find out that porcine pseudorabies has nothing to do with rabies. It’s a herpes virus, and it doesn’t effect humans, but it does kill dogs and other animals, wild and domestic. Once again, ProMed-mail has the needed explanation. Read it here.
Also in the catagory of “needed explanations” and “wildlife disease” is a recent report in the Los Angeles Times of the “first U.S. transmission” of rabies linked to a vampire bat. Uh, no. Even the article says the man was bitten by a vampire bat in Mexico, then traveled to the U.S. Unfortunately, the story was also picked up on the gossip site Gawker.com. Here’s the LA Times story. And here’s a debunking from a biology professor at Long Island University
Finally, the Wisconsin Department of Natural Resources recently launched a new Web site on chronic wasting disease, aimed at hunters. Find the Web site at http://www.knowcwd.com/ And find an article about the Web site and Wisconsin’s “Know CWD” campaign in the Houston Chronicle.
There were just no pretty pictures for this one. Not even a nice picture of a virus available.
Western gray squirrel populations have been declining throughout their range. Recently the California Department of Fish and Game confirmed that the gray squirrel decline in the San Bernardino mountains is being caused by a mange mite, thought to be Notoedres centrifera.
The good news for local residents is that the mite effects only rodents, so dogs and other pets should be safe. The bad news is that the free lunch for squirrels at backyard bird feeders is contributing to the problem, allowing the mite to spread when squirrels gather for a backyard buffet.
The Riverside Press-Enterprise has the news story.
The press release from California Fish and Game has more detail, plus a discussion of other possible causes of the squirrel’s decline.
In other squirrel news, and yes, there is other squirrel news, the squirrel pox that has been killing off native red squirrels in Britain has arrived in Northern Ireland. Squirrel pox was introduced to the region along with North American gray squirrels. The gray squirrels are carriers, and don’t show symptoms. Find the BBC story here.
Photo: Western gray squirrel with no apparent mange symptoms. Click on either of the mange story links for a photo of a symptomatic squirrel. Photo courtesy of California Fish & Game.
Shotgun blast or virus? Who done it? Or what done it? You may have turned to the U.S. Geological Service’s National Wildlife Health Laboratory in Madison, Wisc. to answer some of your most pressing wildlife mysteries. Here’s a view behind the scenes at the lab, with a focus on veterinary pathologist Carol Meteyer, in the current issue of Miller-McCune Magazine.
Washington Department of Fish and Wildlife is making what may be a final attempt to restore the Columbia Basin pygmy rabbit to its native habitat. A 2007 attempt to reintroduce zoo-bred rabbits into the wild ended in most of the naive rabbits being eaten by predators.
This time the rabbits will be released into a fenced enclosure, with gradual exposure to predators through smaller enclosures with tunnels to the outside. The rabbits are not pure-bred Columbia Basin pygmies, but have been bred with pygmy rabbits from Idaho and Oregon, which are not endangered. In fact, most other pygmy rabbits in the West thrive.
Read more in this article in the Idaho Statesman. An InsideScience report on the restoration is available via US News and World Report. Or read the Washington Department of Fish and Wildlife press release. Read the US Fish & Wildlife Service’s species profile (well technically, a “distinct population segment” profile) here.
Photo: A pygmy rabbit of unknown distinct population segment, likely from Idaho, courtesy of the US Fish & Wildlife Service. Photo Credit: R. Dixon (IDFG) and H. Ulmschneider (BLM)