Tag Archives: Mycoplasma ovipneumoniae

WDFW Asks For Public Help Monitoring Okanogan Bighorns After 1 Dies From Sheep Pneumonia

THE FOLLOWING IS A PRESS RELEASE FROM THE WASHINGTON DEPARTMENT OF FISH AND WILDLIFE

The Washington Department of Fish and Wildlife (WDFW) asks members of the public to report sightings of bighorn sheep that are obviously ill in Okanogan County after a bighorn ram from the Mt. Hull herd was recently confirmed to have died from pneumonia caused by a highly infectious bacteria. While posing no health threat to humans, Mycoplasma ovipneumoniae, known as M. ovi, can decimate bighorn populations and kill lambs for many years, preventing herds from repopulating.

A BIGHORN RAM LOOKS OVER THE LOOMIS AREA OF NORTHCENTRAL OKANOGAN COUNTY. (JUSTIN HAUG, WDFW)

At this time, only a single ram from the herd near the Canadian border has tested positive for pneumonia. Testing on additional animals is currently underway. While WDFW biologists and veterinarians await results, they are partnering with biologists at the Colville Tribes to increase visual monitoring of the Mt. Hull herd. And they are asking for help from the public.

“This is a highly visible herd. These sheep are in orchards and among houses,” said WDFW Biologist Jeff Heinlen. “Because we can’t be watching all the time, we are asking people to alert us if they notice sheep that appear lethargic, coughing or showing nasal discharge. This helps us assess the health of the herd.”

There is also a potential for wandering sheep to pass M. ovi to animals in other herds, such as the Omak Lake herd on the Colville Reservation to the south, the Sinlahekin herd to the west, or herds to the north across the border in British Columbia.

“In 2012 the Colville Tribes conducted a genetic analysis between the Sinlahekin, Mt. Hull, and Omak Lake herds, showing us that the Omak Lake herd was likely founded by individuals from the Sinlahekin herd, but may have been in contact through immigration event(s) with the Mt. Hull herd in the past,” said Colville Tribal Biologist Eric Krausz. “We have documented collared bighorn sheep traveling from Omak Lake to Mt. Hull, so we know bighorn sheep from these distinct herds travel back and forth on occasion and likely come into contact with one another.”

Because of this, WDFW asks to also be alerted if bighorn sheep are observed in places they aren’t normally seen. The Mt. Hull herd’s typical range is from approximately Tonasket to the Canadian border north of Oroville. If sheep are seen outside that area, or notably sick bighorn sheep are observed, please call Jeff Heinlen at (509) 826-7372 and leave a message or email Jeffrey.Heinlen@dfw.wa.gov.

While it is biologically possible for uninfected domestic sheep or goats to become infected by contagious bighorns, cross-species transmission of M. ovi is much more common in the reverse direction. The bacteria typically causes only mild and temporary symptoms in domestic sheep and can reduce growth rates, but serious illness and death is rare. In contrast, most bighorns that become infected due to close contact with domestic sheep or goats succumb to pneumonia, and some that survive pass it to newborn lambs that similarly lack immune protection.

There are approximately 17 bighorn sheep herds across Washington, two within the bounds of the Colville Reservation.

OSU Studying Bighorns To Learn More About Risk From ‘Killer’ Bacteria

THE FOLLOWING IS A PRESS RELEASE FROM OREGON STATE UNIVERSITY

With their ability to climb steep rocky mountain areas, California bighorn sheep live in some of the most rugged environments Oregon has to offer.

No matter how high they go, the wild sheep can’t elude Mycoplasma ovipneumoniae – the bacteria now widely thought to be primarily responsible for fatal infectious pneumonia in bighorns. Respiratory disease has killed numerous wild sheep in Oregon and other Western states over the past few decades and is considered the largest risk to wild sheep populations, according to the Oregon Department of Fish and Wildlife.

A SOUTHEAST OREGON BIGHORN EWE GUARDS HER LAMB. THE WILD SHEEP ARE EXTREMELY SUSCEPTIBLE TO A BACTERIA FOUND IN DOMESTIC HERDS, AND OREGON STATE UNIVERSITY IS TRYING TO LEARN MORE ABOUT HOW BEHAVIORS OF CALIFORNIA BIGHORNS AFFECT THEIR RISK OF CATCHING THE DISEASE AND DYING. (ROBERT SPAAN)

Once a herd is infected, an all-age die-off can occur, and the disease remains chronic in the population.

Now, Oregon State University researchers are studying several aspects of the California bighorn sheep herd in the state – including movement, habitat use and survival – to gain insight into the animal’s risk for contracting the killer strain known as M. ovi (pronounced m-ovee). The disease spreads through contact between domestic sheep flocks and bighorn sheep, or from bighorn to bighorn.

Oregon is home to about 3,700 California bighorn sheep in 32 different herds in central and southeast Oregon. ODFW traditionally captures and relocates California bighorn sheep around the state each year to improve genetic diversity and restore this rare species to its historic range in Oregon. But these relocation efforts are on hold this year while wildlife managers learn more about M. ovi, partly through the work being done at OSU.

Often, the first contact with a particular strain of pneumonia kills bighorn of all ages, according to OSU wildlife biologist Clint Epps. Some adults survive, but then as the infection persists their lambs die every year. A bighorn herd might not recover for decades.

Wildlife managers strive to keep wild and domestic sheep and goats separate to avoid transmission of the disease.

“There is a high-stakes need to understand where the pathogen is likely to enter a bighorn population and where it’s likely move after that,” Epps said. “In the past few years, wildlife agencies in the West have made decisions to remove certain individual animals, or all individuals in the herd, to prevent the spread of disease.”

A die-off of the bighorn sheep herd in the Lower Owhyee River Canyon in 2015-16 raised concerns about how M. ovi is impacting Oregon’s wild sheep populations. Also, that year the Nevada Department of Wildlife made the difficult choice to euthanize an entire herd of sick bighorn sheep just south of Oregon’s border to stop the spread of M. ovi to neighboring populations.

In 2011, ODFW had to kill five of the 20 bighorn sheep reintroduced to the John Day Fossil Beds after they wandered into an area where they could have been exposed to a domestic sheep farm.

“There’s been a tremendous amount of effort to increase these bighorn populations, and our goal is to provide better information when they make those decisions,” Epps said.

ODFW wildlife biologists and veterinarians have sampled and collared more than 120 California bighorn sheep in the past two years. Recent samples from those captured bighorn sheep, some of which were tested at OSU’s Veterinary Diagnostic Laboratory, will provide extensive information on diseases and animal health, including determining whether the strain that eliminated the Nevada herd has spread to Oregon’s bighorn sheep.

Robert Spaan, an OSU doctoral student, travels to southeastern Oregon from April to August to study the California bighorn sheep herds, which each typically number between 30 and 150 individuals. He tracks the bighorn sheep that have been fitted with GPS collars by ODFW and records birth and death data.

“We’re able to respond to mortalities, and we are able to determine cause of death in most cases,” Spaan said. “We managed to detect a die-off of lambs in one population last year, the only one where we saw active M. ovi infection.”

Disease was one of the factors when bighorn sheep died off in Oregon in 1940s, along with unregulated hunting. But sport hunters have since been instrumental in restoring bighorn sheep in Oregon. Oregon Department of Fish and Wildlife’s annual auction and raffle of special bighorn sheep tags have generated thousands of dollars for their management and for research.

Among the funders of the study are the Oregon Department of Fish and Wildlife and the Oregon Foundation for North American Wild Sheep.