Wildlife veterinarians suspect a mysterious disease causing hoof deformities in elk herds across Southwest Washington has now crossed into Oregon.
Sporadic cases of deformities have been around for decades, but in recent years there have been more frequent sightings of clusters of elk hobbling because their hooves are missing or malformed.
Documented cases had been confined to Southwest Washington. But two hoof samples hunters took in Multnomah and Clackamas counties in Northwest Oregon show similarities to cases of the condition often referred to as elk hoof rot.
Julia Burco a veterinarian with the Oregon Department of Fish and Wildlife, said the the physical appearance, the geography and the presence of a certain bacteria in the samples all resemble cases from Washington.
"From the lesions it looks very similar. And that's kind of our presumptuous diagnosis which is why we're going to be pretty vigilant about taking additional samples on anything that comes through our lab," Burco said.
Burco and her colleagues first received the samples in March and immediately suspected elk hoof disease, but are still running tests to rule out any other possible causes for the deformities.
"No wildlife disease respects state borders," she said. "I wasn't too surprised."
The Oregon Department of Fish and Wildlife plans to increase its surveillance and to create a website where the public can report suspected cases. Washington already has such a tool.
Scientists think the hoof rot itself may be caused by a bacterial disease similar to one found in livestock.
The Washington Department of Wildlife and others in the region have also spent years studying the deformations and reached no firm answers on why they're spreading or how to stop them, but that hasn't stopped the state from trying.
At its August meetings, the Washington Fish and Wildlife Commission is considering a new requirement that hunters leave the hooves of any elk taken in areas known to be affected by the disease, in the hopes of slowing its spread.
Several environmental groups blame herbicides, either directly or indirectly, for the recent spread of the disease.
"I'm not saying that herbicides are causing the problem. What I'm saying is they make the animals more vulnerable to this infection or to any infection," said Bob Ferris, executive director of Cascadia Wildlands. "There are some problems with the habitat that are affecting the overall health of the animals, and that's an area that we need to look at as well."
Biologists and veterinarians in Oregon and Washington have not confirmed a connection between herbicides and hoof deformities but are investigating possible environmental causes.