State wildlife managers believe they are close to determining the cause of hoof disease in southwest Washington elk and plan to hold two meetings in April – in Vancouver and Chehalis - to share results to date and answer questions from the public.
Sandra Jonker, Washington State Department of Fish & Wildlife regional wildlife manager, said department staff will discuss results to date of ongoing tests designed to identify the cause of deformed or missing hooves in elk, primarily in Cowlitz, Pacific and Wahkiakum counties.
Since 2009, WDFW has collected tissue samples from 43 elk for testing at diagnostic laboratories at Washington State University, Colorado State University, the University of Wyoming, the USDA National Animal Disease Center and the University of Liverpool in England.
Jonker said recent tests of diseased hooves point to the presence of treponeme bacteria, which have been linked to hoof disease in cows and sheep in many parts of the world.
“It’s premature to announce a final diagnosis, but tests from three independent diagnostic labs appear to show an association between the diseased hooves and the presence of treponeme bacteria,” Jonker said.
“That’s a real concern, because the options for treating the disease are extremely limited.”
Kristin Mansfield, WDFW epidemiologist, said treponemes have been linked to an increasing incidence of hoof disease in livestock for two decades, but have never been documented in elk or other wildlife.
There is no evidence that these bacteria are harmful to humans, she said, noting that tests indicate the disease is limited to hooves and does not affect the animals’ meat or organs.
Mansfield said scientists believe animals pick up and transmit the disease through wet soil, characteristic of the lowlands of southwest Washington. Livestock infected with treponeme bacteria may respond to repeated courses of antibiotics, but frequently become re-infected once they are returned to pasture, she said.
“Unfortunately, there is no vaccine for this disease,” she said. “Livestock that don’t respond to treatment or become re-infected after treatment are usually sent to market and slaughtered.”
Meanwhile, WDFW is developing a management approach based on input from WDFW staff and two advisory groups created to help guide the department’s course.
“As with many wildlife diseases, there are no easy answers to this problem,” Jonker said. “But we need to be ready to take action, because doing nothing is not an option.”
As a precautionary measure, WDFW will ask state officials to adopt a new regulation requiring hunters to remove the hooves of any elk taken in southwest Washington and leave them in the area to prevent the disease from spreading.