Margaret Wild describes the meticulous research required of scientists and game managers to unravel the cause of a new wildlife disease as similar to the work of detectives sifting through a complicated crime scene.
Each piece of evidence could be a critical bit of information that leads to a conviction. It could also be a confounding factor unrelated to the quest. It takes time, diligence and perseverance before an answer is found.
In this case the would-be crime is the sudden emergence of elk hoof disease in some western Washington elk herds. The disease first popped up 2008 and is expanding its geographic scope. It was detected on the east side of the Cascade Mountains for the first time last spring in western Klickitat County near Trout Lake. It causes sores and lesions on the feet of elk, making them lame and often leading to death.
Wild was hired by Washington State University’s Department of Veterinary Microbiology and Pathology at the College of Veterinary Medicine in Pullman to lead an effort there to study the disease and hopefully come up with, if not a cure, steps wildlife managers can take to mitigate its effects. Her position was made possible by funding from the Washington Legislature.
Wild previously served as the national wildlife health lead and supervisor for the Wildlife Health Branch of the National Park Service at Fort Collins, Colo. She has vast experience working on Chronic Wasting Disease that infects deer herds in the Midwest and was recently discovered in Montana.
She and others at WSU are working with counterparts at the Washington Department of Fish and Wildlife. Even before she started, researchers uncovered a key trigger of the disease. They analyzed bacteria sampled from the hooves of infected elk and isolated a specific family — treponeme — that appears to be associated with the ailment. The disease, which has at times wrongly been called elk hoof rot disease, is now known as treponeme-associated hoof disease.
Wild began her new job last month and is eager to learn more about how elk hoof disease is spread and what types of environments it flourishes in.
“There is likely something that is setting these elk up to have the infection,” she said. “We don’t know what that is right now.”
For example, the researchers want to know if there are other factors besides the bacteria that make elk susceptible.
“It could be things that alter where the animals live or how much contact they have with other elk or how their immune system works or what the composition of microbacteria in the soil is,” Wild said. “Those are things we need to take a look at.”
Thus far, researchers believe the moist soil conditions found on the west side of the state play an important role in the ability of the disease to quickly spread. However, they can’t rule out the possibility that it could one day infect elk in the much more dry regions of the state. The area in which it was found on the east side of the Cascades is far wetter than the environment of, say, the Blue Mountains in the state’s far southeastern corner.
“It gets quite a bit of precipitation, lots of snow,” said Kyle Garrison, elk hoof disease coordinator for the Washington Department of Fish and Wildlife of the Trout Lake area.
“I think we can make the hypothesis it’s going to be worse in wetter areas, but we don’t know that for certain yet. That is why it’s important to look at the whole picture to figure out which environmental factors are important, what density of elk is important,” Wild said. “I’m hopeful it’s going to be harder for the disease to take hold in areas that are not as wet, but I don’t think we should completely rely on that not being the case without investigating.”
Wild hopes to start working with captive elk as part of the research. She doesn’t yet know where that might take place. Both she and Garrison also want to find herds that have had a few elk infected with the disease but where it has not yet become rampant.
“What are the important characteristics of those sites where the disease would occur at a lower prevalence versus where we see outbreaks,” she said. “Is there anything we can learn in that location that can help us learn what factors are important in the development of the disease?”
Garrison said the department is monitoring the herds where the disease is common and taking a more active role in herds where it is new. For example, he said afflicted elk in the Trout Lake area are being removed by the department in an effort to stop its spread. But in the Mount St. Helens area where it is common in herds, culling infected animals is not an option without seriously affecting population numbers.
He said hunters and others who recreate outdoors can help monitor the disease by reporting any elk they see that are limping. Hunters who kill elk with deformed hooves or any hoof abnormalities are being asked to report them to the department.
Those who see something suspicious can submit a report online at https://wdfw.wa.gov/conservation/health/hoof_disease/ or contact Garrison at Kyle.Garrison@dfw.wa.gov.
Garrison said limping doesn’t necessarily mean an elk has the disease.
“When you are in southwest Washington and see a limping elk and multiple limping elk, you can probably be pretty confident it is probably treponeme-associated hoof disease. But if it’s in eastern Washington and you see one limping elk in a group of elk, that is unlikely to be treponeme-associated hoof disease. It could be a broken leg.” he said.
“Elk lead tough lives, and things happen to their legs and hooves quite often.”
The department is asking successful elk hunters to leave elk hooves in the field to prevent against transmitting the disease to other areas.
Barker may be contacted at firstname.lastname@example.org or at (208) 848-2273. Follow him on Twitter @ezebarker.