A Solution For Bear Mange in Virginia?

Sep 7, 2018

Virginia biologists have their eyes on a number of problems in the state, such as giant hogweed and Chronic Wasting Disease in deer. Another problem on the rise – mange in black bears – might have a new treatment, as WMRA’s Christopher Clymer Kurtz reports.

Fred Frenzel is a district biologist with the Virginia Department of Game and Inland Fisheries. He’s based in Edinburg, and serves Fauquier, Frederick, Clarke, Shenandoah and Warren counties – and he has a name for his part of the state.

FRED FRENZEL: I sort of semi-jokingly refer to my area as the “district of pestilence.” It seems like if something strange is going to occur, it’s going to be here.

The dangerous giant hogweed has been found here, and elsewhere in the state. It can cause vision problems, and, if you get its sap on your skin in sunlight, blistering and severe burns. And it’s big.

FRENZEL: I’ve heard folks describe as like Queen Anne’s lace on steroids.

Then there’s Chronic Wasting Disease, a fatal neurological disease found in about 40 deer here since 2009. Frenzel’s district includes a “containment area”: whole deer carcasses can’t be transported  out of the four-county area, and there’s a carcass testing program during deer hunting seasons.

The longhorn tick has shown up here, and elsewhere. Frenzel said he’s not a tick guy, but he’s read it can carry pretty much all the tick-borne human diseases.

FRENZEL: It sounds like the things they make horror movies out of. But yeah, it’s in my district, too.

And there’s mange in bears. It’s shown up in other states including Pennsylvania, where it’s a bigger problem, but it’s now spreading across Virginia after first appearing in – you guessed it – Frenzel’s district. There have been close to 40 sightings or captures of bears with mange in Virginia since 2014.

The Wildlife Center of Virginia near Waynesboro has received several bears with advanced cases. Ed Clark, the center’s president and founder, explains how serious mange is:

ED CLARK: It’s a skin mite that embeds itself in the skin of the host animal, and the inflammation that comes from their bites and embedding their tiny little bodies inside the hair follicles of affected animals, is skin inflammation that causes the hair to fall out. The proliferation of these mites can quite literally drain the blood of the animal ... to the point that it can weaken and kill the host animal.

Mange in bears isn’t new, but biologist Frenzel said the mange that’s been on the rise in the last few years – it’s called sarcoptic mange – is caused by a different mite, one that’s typically found on canines, not bears.

CLYMER KURTZ: Does that say to you, that the mites are adapting, or that the bears have developed a vulnerability?

FRENZEL: We don’t know. We don’t know. I mean, anything along that line is just speculation. It would seem it’s got to be one or the other of those things. This species of mite has been around pretty much forever, and the bears have been, too, and it’s never been a problem for them, so something’s changed, but we don’t know what that is.

It’s not a pretty disease in bears.

FRENZEL: The ones we’ve dealt with a lot are in the later stages of the disease. Typically they lose a lot of hair, their skin gets really thick and crusty, they are really skinny, they become really lethargic, just sit around, just walk around, they don’t really run. They just kind of hang out and they act really apathetic. They might sit there in your yard and look at you. Walk right up to one, and it just sits there and looks at you as if, you know, it doesn’t care.

There’s some good news in the works, though, for bears with mange, no matter the kind of mite infecting them. The commonly used drug for treatment has been Ivermectin, which requires two doses days apart. That’s not conducive to administering to animals in the wild. But the Wildlife Center is researching a different drug – Bravecto – that could be used to treat bears with mange. It requires just one dose, perhaps planted in a donut and fed to an infected bear.

Veterinarian Peach Van Wick is a wildlife research fellow at the Wildlife Center.

PEACH VAN WICK: Overall, we’re really happy with the results that we’ve seen, and proud of the bears that we have treated and that have gotten a lot better…. They come in just so affected … and then we’ve been giving them this medication and then even a few weeks later, you know, they’re eating everything, they’re feisty, they’re angry whenever we approach them, so they start acting more like bears. And that’s exactly what we want to see.

There’s still more to learn about the use of the drug in bears, for example how quickly it disappears from bears’ bloodstream and tissues, particularly if it’s to be used in the wild where people hunt bears for food.

In the meantime, Clark said,

CLARK: Well, to say that we’re excited about it is sort of an understatement. We are absolutely astonished at the results we have gotten with some of these severe cases, and we are very optimistic and very hopeful that through our clinical work we will have discovered and developed a technique and a protocol for using this medication in the field that could quite literally save the lives of hundreds of bears. It’s pretty cool.