Wildlife biologists are hoping hunters and the general public will help them identify potential cases of crippling hoof disease in Roosevelt elk to allow further study.
Although not yet found in Curry County, the disease is spreading in other parts of Oregon and has been identified in nearby Del Norte County, California.
Treponeme-associated hoof disease (TAHD) — commonly referred to as “elk hoof disease” — can cause deformed, overgrown and otherwise damaged hooves. The lesions and resulting deformities are painful and lead to limping, lameness and even death as observed in other states. When the disease is severe, elk may become too weak to graze, fight off other infections or escape predators.
In a recent presentation to the Del Norte County Board of Supervisors, California Department of Fish and Wildlife veterinarian Emma Lantz said the disease was discovered in April in two Roosevelt elk from a resident herd in Del Norte County.
She explained that scientists received increased reports of lameness in elk starting in the 1990s, but the disease was first described in Washington in 2007 and 2009. It has since spread to elk in Oregon, Idaho and California.
According to a fact sheet from the Oregon Department of Fish and Wildlife, there have been nearly 50 confirmed cases, and more than 220 separate reports of limping elk or elk with deformed hooves since 2013. A majority of the reports have been from the northwestern corner of the state, but an increasing number of cases are also showing up in northeast Oregon and now has been moving down south into Lane and Douglas counties. So far none have been identified in Curry County, although biologists have speculated that they may be present.
“We’re still getting an understanding in the landscape,” Lantz said. “Diagnosis is postmortem, so we need dead animals to sample for TAHD. We can look for lameness and limping when the animals are alive.”
She said treponeme-associated diseases are present in livestock, but there’s currently no evidence that TAHD has been transmitted between elk and cattle. She added that the CDFW is still working with its counterparts in Oregon and Washington to determine whether it’s possible for TAHD to be transmitted between the species.
In the same presentation, Senior Environmental Scientist Shawn Fresz said CDFW staff in the northern region will conduct surveillance from “hunter-harvested elk” taken in Del Norte and Humboldt counties. He said hunters can play an important role by submitting samples to the department.
“Full cooperation would mean we would collect approximately 126 samples of harvested elk during this 2020 hunt season,” Fresz said. “Hunters would be requested to bring the head, liver and all four legs intact to either our department office in Eureka or to our check station that we will be manning throughout the hunting season at Lake Earl.”
While the disease appears to be highly infectious among elk, there is no evidence that it affects humans. Still, biologists recommend that hunters who harvest an elk exhibiting signs of deformed or damaged hooves should exercise caution and practice safe hygiene when processing, cooking and consuming the meat.
It is unknown what impact TAHD may have on elk populations in California or other states. California is home to three subspecies of elk — Rocky Mountain elk, Roosevelt elk and tule elk — that together inhabit about 25 percent of the state. In other states, both Rocky Mountain and Roosevelt elk have contracted TAHD. To date, there are no known cases of TAHD among tule elk.
“After the first confirmed case of elk hoof disease, the northern region began documenting the occurrence of any elk that were limping, were less than ideal body conditions — so they were thin or emaciated — or had evidence of diarrhea and had visible abnormal hoof growth,” Fresz said. “Focused surveillance through regular visual observations will continue occur on the affected herd, adjacent herds and other resident herds of wet substrates with significant livestock overlap in Del Norte and Humboldt counties.”
Lantz added that the disease is difficult to eradicate once it’s present in elk or livestock. She pointed out that in livestock, digital dermatitis is often found on a dairy and can be managed by treating the lesions it causes. But the only option wildlife biologists have, she said, is lethal removal.
“Because we don’t have a great understanding of the disease in general it’s going to take some time to see what the effects are of lethal removal,” Lantz said. “Animal welfare is also a priority for us because of the severity of this disease and how does it affect its ability to graze.”
The general public can assist by reporting any elk that appears to be limping, lame or have abnormal hooves.
Websites for both California and Oregon provide an easy way to do reporting:
Oregon: http://www.dfw.state.or.us/wildlife/health_program/elk_hoof_disease/, which can be found at www.odfw.com (or call at 1-866-968-2600).