What To Do If You Come Across Deer With A Deadly Brain Disease Recently Confirmed In California

A deadly neurologic disease has been confirmed in California’s deer and elk population for the first time.

The California Department of Fish and Wildlife announced Tuesday that they’ve detected two cases of chronic wasting disease (CWD) in dead deer found around the Sierra National Forest.

There’s no vaccine or treatments available, and the incubation period can be months to even years, making the disease difficult to control. People are being asked to help slow the spread by reporting any signs of illness in these animals to state wildlife officials.

What you should know about chronic wasting disease

The disease affects deer, elk, moose, and reindeer. It’s been detected in 33 other states across the country, parts of Canada, and Scandinavia since it was first identified in 1967.

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Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told LAist it’s a progressive, prion-related disease that basically causes the animals to waste away, hence the name.

“A prion is a piece of protein that's in our cells, that if it gets misfolded, it actually can then cause that cell to be destroyed,” he said.

The disease can lead to a lack of coordination, drooling, excessive thirst, and behavioral changes. And once symptoms start to show, death is usually close behind.

It’s believed to be spread by direct, or indirect contact, with bodily fluids and tissues. But most infected deer don’t show signs early on, which Osterholm said is a challenge.

“It will first be found in just several deer, either roadkill or hunted, but then it typically spreads rather quickly, and we see those numbers increasing,” he said. “So today, wherever CWD has been identified, you can count on it expanding its boundaries and also the number of deer within those boundaries where the infection occurs.”

For example, Osterholm said there’s counties in Wisconsin where 80% of the deer population has CWD.

“We're literally watching kind of a slow moving prion tsunami take over,” he said. “And the question is, what will this do to the wildlife?”

About the California cases

One case was in Madera County near Yosemite Lakes, and the other was in Inyo County near Bishop.

The first deer had died of unknown causes, and the second was found after being hit by a vehicle. Officials took samples from both and they were confirmed to have CWD earlier this week.

The California Department of Fish and Wildlife said in a statement that the distance between the deer means the disease has probably been in the state for some time.

“CWD infected animals can excrete infectious prions before clinical signs appear, and these prions can persist in the environment for years, making it very difficult to prevent or control the spread once it has been introduced,” Brandon Munk, the department’s wildlife veterinarian who oversees CWD surveillance and response efforts, said in a statement.

Officials have been monitoring California’s elk and deer populations through lymph node sampling for decades, with more than 6,500 animals being tested in that time.

What to do if you see a sick deer or elk

If you see a deer or elk that is moving strangely or acting unusual, you should report those signs of sickness here.

Try to gather as many details about the animal and its environment, but do not touch or move them.

Hunters are also being asked to test their harvest and voluntarily participate in the statewide surveillance program.

“We hope that there's never going to be a human case associated with consumption of venison from these deer,” Osterholm said. “However, we can't count on that. And so one of the things that we really emphasize to hunters is the way they can protect themselves from that happening is by testing the deer to make sure that it is not infected with this prion.”

Hunters can find more information on how to help here.