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In other animals, mange spreads most rapidly in urban areas. But in Virginia's black bears, mange seems to spread just as quickly in rural parts of the state. Photo courtesy of the Virginia Department of Wildlife Resources.

Highly contagious bear disease causes hair loss, painful, itchy scale-like skin

On a sunny afternoon late last week, Rappahannock County Supervisor Keir Whitson was working from his home in Harris Hollow when he heard a thump at the door. When he went to investigate, he found a black bear in his front yard. This particular bear, like a growing number of individuals across the mid-Atlantic, was suffering from sarcoptic mange.

“The poor guy had crawled beneath a small maple tree next to our door, presumably to get warm against the stone on our house and steps,” Whitson said. “He was there for 15 or 20 minutes, then went up to my neighbor’s house on the mountain above me and went straight up on her porch.” 

Whitson immediately contacted the Virginia Department of Wildlife Resources, the government agency responsible for tracking and managing cases of mange.

Bears with severe cases of this highly contagious disease will typically suffer from hair loss and painful, itchy scale-like skin, and they may seem indifferent to their surroundings. Oftentimes they are also emaciated and uninterested in food. But without a winter coat, they can sometimes look in unusual places for warmth.

Mange is caused by Sarcoptes scabiei, a burrowing mite that commonly infects wild and domestic animals and can create a condition known as scabies in humans. In fact, it is one of the earliest known human diseases, having been recognized since biblical times. But in North American black bears, the disease was historically rare until very recently. 

The first report of a black bear with mange was made in Michigan in 1984. In the early 1990s, sarcoptic mange spread among black bears in Pennsylvania and has continued over the past 30 years to impact populations in New York, West Virginia, Virginia and Maryland. 

Here in the commonwealth, David Kocka, a biologist for the Virginia Department of Wildlife Resources, said that mange has been on the landscape for about 10 years. In the past three years, however, his office has seen a 300% increase in cases of mange within a 12 county area. In 2020, six bears in Rappahannock County were identified as having the disease.

“There’s a lot that we are not currently understanding about mange in bears,” Kocka said. “I guess the biggest question is why all of a sudden we’re seeing bears impacted by mange? This has been on the landscape forever, why all of a sudden it’s impacting bears, we don’t know.”

Mites are most often transmitted between hosts through direct contact, but bears are not social animals for much of the year. So how are they still catching the mites?

Studies show that when conditions are favorable — around 50 degrees Ferenheit — mites can survive without a host for several weeks. We can’t know for certain, but some biologists have hypothesized that climate change, increased contact with humans, and anthropogenic impacts to environmental health could be factors in making bears more susceptible to mange. 

Even though mange is easy to treat in humans and domestic animals, it’s not so easy to treat in bears. 

Kocka said that the DWR did experiment at one point with rehabilitating bears, but to no avail. 

“We treated several bears and released them once they had been cleaned up and put radio collars on them,” Kocka said, “but a high percentage of those bears eventually came down with another case of mange a year or two down the road, the same or even worse.”

Sadly, Kocka said, bears with severe cases of mange have to be humanely euthanized.

According to Kocka, the kindest thing to do if you’re concerned about bears is not to feed them or leave anything outside your house that might attract bears.

“It is illegal to directly or indirectly feed a bear in Virginia,” he said. “The reason we do that is because any time you congregate animals to a food source you run the risk of spreading something. And it doesn’t have to be that there are five bears at your bird feeder at one time, but if one bear sheds a couple mites and another bear comes in and picks up those mites, they can attack him.”

If you see a bear that you suspect has mange, call the Virginia Wildlife Conflict Helpline at 1-855-571-9003. 



 

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