Category Archives: disease

Infection and Capture Fatalities

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It happens. An animal is captured for study, is released, but dies soon after. A certain percentage of fatalities is expected in any study where animals are handled. In Chile recently, five fur seal pups died after being captured, AAAS’s ScienceShot reports. There had been no previous fatalities in the four years of the study.

Veterinarians studying the dead pups found they all had a hookworm infection. The infection sent the seals’ adrenal glands into over-drive, stressing their hearts. The researchers say that fieldworkers should not try to capture seals that show signs of chronic infection, which is probably good advice when working with other animals as well.

Read the ScienceShot article here. It includes links to the paper and other information.

 

Elk Killed by Blue-Green Algae

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More Cervid Contraception: GonaCon and ElkOutbreaks of blue-green algae are a growing plague across the country. Pollution plays a role, by providing nutrients (the pollution is typically fertilizer, but also detergents containing phosphates) that allow the algae (which isn’t really algae, but a photosynthetic bacteria — read more here) to grow to unnatural levels.

The toxins in blue-green algae can kill animals such as dogs or cattle that drink the water. Children are at higher risk from blue-green algae toxins than adults for the same reason; they are more likely to drink water while swimming. Hot weather and still lakes or ponds make things worse, leading some states to produce regular reports on where blue-green algae is found.

A mysterious die-off of 100 elk in New Mexico appears to have been caused by blue-green algae, an article in the Southwest Farm Press reports. Biologists from the New Mexico Department of Game & Fish considered many common causes of elk death, including epizootic hemorrhagic disease, anthrax and lightning.

A search of nearby water sources found blue-green algae in fiberglass water tanks in the area where the elk died, but not in ceramic water tanks in the same area. Just another possibility to consider when you are faced with an unexplained wildlife die-off.

Read the entire article in the Southwest Farm Press.

Photo: Photo: A healthy bull elk. Credit: Gary Zahm, courtesy of US Fish and Wildlife Service

Zombies vs. Wildlife

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Can I be Boing Boing when I grow up? Last week it ran a post by National Wildlife Federation naturalist David Mizejewski on how wildlife would save us if there were ever a zombie attack and if whatever caused zombification only affected humans.

“If there was ever a zombie uprising, wildlife would kick its ass,” Mizejewski says in the piece.

What follows is an overview of wildlife’s role in cleaning up the undead, from carrion eating birds, to carnivores that will go for anything slow-moving, to detritivores like maggots and beetles. It’s got lots of videos, so this is not lunchtime reading.

Our cultural zombie moment is peaking now, so enjoy. But when zombies finally jump the shark, remember, you heard it here first. (Well, second.)

“Zombies vs. animals” in Boing Boing, here.

Antibiotic Resistance Spreads to Wildlife

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m_crow_5Antibiotic resistance isn’t just for humans and farm animals. An article in Environmental Health News says that antibiotic resistance has been found in crows, gulls, houseflies, moths, foxes, frogs, sharks and whales. You can follow links in the article to get to the journal article with the findings for each of those groups.

The big question raised in the article is, what is the implication for human health? Nobody really knows. But certainly, if you are handling wildlife, these findings give you a reason to be even more cautious. And they certainly have implications for wildlife rehabilitation.

Read the entire article in Environmental Health News.
The article focuses on a recent crow study, and you can find the abstract for that here.

Photo: Crow. By David Herr, courtesy US Forest Service

Plague: Human Cases in NM, Squirrel Case in Cal.

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New Mexico has had all three cases of plague in humans that have occurred in the United States this year, a New Mexico Department of Health press release reports.

Read the press release here. (Will open a PDF.)

The bacteria that causes plague is endemic in the southwestern US. Wildlife cases are so common that I don’t report them here, but those cases can be an important warning to locals to take extra care to keep their pets away from wildlife and to avoid flea bites, and for wildlife managers and researchers to take precautions as well.

Just such a warning is in place in Palomar, California, where ground squirrels at a campground have been diagnosed with plague.

Read the story in the San Diego Union-Tribune.

Plague: Human Cases in NM, Squirrel Case in Cal.

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New Mexico has had all three cases of plague in humans that have occurred in the United States this year, a New Mexico Department of Health press release reports.

Read the press release here. (Will open a PDF.)

The bacteria that causes plague is endemic in the southwestern US. Wildlife cases are so common that I don’t report them here, but those cases can be an important warning to locals to take extra care to keep their pets away from wildlife and to avoid flea bites, and for wildlife managers and researchers to take precautions as well.

Just such a warning is in place in Palomar, California, where ground squirrels at a campground have been diagnosed with plague.

Read the story in the San Diego Union-Tribune.

CWD in Plants

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cwd_map 9-30-13Plants, including crop plants such as alfalfa and tomatoes, may serve as a reservoir for the prions, or misfolded proteins, that cause chronic wasting disease in deer (as well as other prion diseases such as scrapie in sheep, and mad cow disease), reports WisconsinWatch after a careful reading of the The Wildlife Society conference program.

WisconsinWatch is produced by the Wisconsin Center for Investigative Journalism. And they certainly investigated here.

Christopher Johnson, U.S. Geological Survey’s National Wildlife Health Center will present a talk on his research at the conference on October 7.

Oh, and Johnson found that the prions from plants were infectious when injected into mice.

I’m going to skip right over the scary prospect of plants as a reservoir for prion diseases and go right to the next point made in the WisconsinWatch article: this finding is not going to change the fact that the Wisconsin Department of Natural Resources has pretty much given up on managing CWD in the state.

Johnson’s findings have not yet been published in a scientific journal, and it appears that the National Wildlife Health Center has not yet released a report or a press release on the research.

Find The Wildlife Society Conference abstract here.
Read the WisconsinWatch article here.

Map: Incidents of CWD, courtesy of USGS National Wildlife Health Center

Pond Study Points to Chytrid Reservoir

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pond research chytridAbout a third of the ponds in a Missouri study harbored chytrid fungus. A Washington University in St. Louis scientist decided to take advantage of the fact that the fungus does not seem to cause amphibian deaths in the region, and tried to tease out the factors that lead to the fungus flourishing in one pond and not another.

The 29 ponds studied were all roughly the same size and depth. They were clustered in the east-central section of Missouri (no surprise, around St. Louis).

No single factor determined which ponds had the fungus and which did not. But some fancy statistical analysis showed that the affected ponds shared amphibian community structure, macroinvertebrate community structure, and pond physicochemistry.

Since the research was done, crayfish and nematodes have been found to be infected with the chytrid fungus, making them possible reservoirs for the disease. This study suggested that variations in invertebrate communities was a factor in which ponds harbored the fungus.

In the paper, which was published in PLoS ONE, the researchers recommend that more research be done on the non-amphibian life in infected ponds to figure out how they are contributing to sustaining the fungus.

Read the Washington University in St. Louis article here.
Read the PLoS ONE paper here.

Photo: A pond survey crew samples the creatures that live in a Missouri pond in order to better understand the differences between ecosystems that favor chytrid and those that do not. Alex Strauss, the first author on this paper, is wearing a blue shirt.  Photo credit: Elizabeth Biro/Washington University – Tyson Research Center

EHD News

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It’s been a quiet summer for epizootic hemorrhagic disease (EHD) in deer. Either conditions didn’t favor the biting midges that spread the disease among deer, or the northern states that experience periodic fatal outbreaks of the disease are becoming used to the new normal.

EHD season isn’t over, though, as these two news items show. Reuters says that wildlife managers in Montana are trying to pin down the cause of death for 100 white-tailed deer along the Clark Fork River. EHD had not been previously found in Montana west of the Continental Divide, the article says.

Read the Reuters story here.

In North Dakota, there is no doubt that EHD is the cause of deer deaths there. An Associated Press story says that North Dakota’s Game and Fish Department has suspended the sale of 1,000 doe hunting licenses because of an EHD outbreak that began in August and continues, the article quotes ND wildlife Chief Randy Kreil as saying.

Read the AP article in South Carolina’s The State, here.

 

Newly Discovered Chytrid Fungus

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fire salamanderA new species of chytrid fungus has a different ecological niche than the one that has been wiping out amphibians all over the globe, says John Platt it Scientific American’s Extinction Countdown blog.

The familiar strain of chytrid fungus thrived in warmer temperatures. The newly discovered species thrives at lower temperatures, the blog post says. The fungus was identified in salamanders in the Netherlands. Midwife toads exposed to the fungus in the lab did not die.

Is this good news or bad news? It could be good news if the fungus is only lethal to a small number of species and is only viable in a certain temperature range. Limits are good when it comes to chytrid fungi.

However, if this species of chytrid fungus is totally different from the other species that has already done a good job of wiping out amphibians worldwide in everything but how lethal it is — in could just hit amphibian species and environments that the other species hasn’t gotten to yet, which would be very bad news indeed.

Read the Extinction Countdown blog post here.
Read the Proceedings of the National Academy of Sciences paper here. (Fee or subscription required for full article.)

Photo: Fire salamander in France, by Didier Descouens. Used under Creative Commons agreement.