Deadly deer virus hits New York hard

Abby Ridgeway was walking her dog on September 16 when she saw a downed deer in her wooded backyard in Campbell Hall, N.Y. The deer was picking its head up slowly and putting it back down, unconcerned that Ridgeway and her dog were within 40 feet of it. Ridgeway, 22, could tell that the deer was going to die – but of what? It didn’t look wounded or old.

Curious, she googled “deer disease.” The search suggestion brought up “deer disease Hudson Valley.” That was how she learned about epizootic hemorrhagic disease, yet another virus that’s rampaging through a population that has no immunity to it. This one does not affect humans, but it has been decimating white-tailed deer on both sides of the Hudson.

As of mid-October, the New York State Department of Environmental Conservation (DEC) had received 1,195 reports of sick or dead deer in seven counties. The stench of rotting carcasses has become all-too familiar in the epicenters of Putnam, southwest Dutchess, and eastern Orange counties. This is New York’s third outbreak, and, according to DEC spokesperson Wendy Rosenbach, the worst one yet.

Ridgeway called the New York State Department of Conservation to report the dying deer. Yes, it sounded like another case of EHD, they confirmed, and that the deer would probably die within a day or so. Transmitted by the bite of a midge or “no-see-um,” once infection sets in – with symptoms that can include swollen head, neck, tongue, or eyelids, foaming at the mouth and loss of fear of humans – death tends to follow swiftly, within eight to 36 hours.

Nearly a month later, Ridgeway can still smell the rotting deer from her house when her windows are open. “It’s a smell I’ve been smelling all around Orange County, driving around with my windows down,” she said. Between her property and her two neighbors’, that dying deer was one of five to turn up dead on the five-acre swath of land in her immediate vicinity. “We have a lot of swamps around here so that’s probably why,” she said. She has not seen a healthy deer at all this season.

“Deer are just dropping left and right,” said Brandon Kafka, 28, of Rock Tavern, a union utility inspector and avid outdoorsman who relies on his annual venison harvest as his sole meat source. Kafka has seen several dead deer in Stewart State Forest, one of his hunting spots – in or near water, a telltale sign of this disease, which makes feverish deer thirsty.

Bow hunting season so far has “been super light,” said Kafka, a past-president of the Rockland County Trappers Association who’s been hunting, fishing and trapping since age 12. “I used to see anywhere from 10 to 20 deer a day, and just yesterday I only saw three youngsters. I’ve never seen anything like this before. It’s worse than Covid for deer. This is more like a plague.”

‘2020 strikes again’

Diana KyDon, a big game hunter for 22 years, found six dead deer along a 200-yard stretch of stream on her property in Chester. That’s not out of the ordinary, she said. In the area of Stewart State Forest, hunters are finding about one dead deer per acre, said KyDon, a delegate of the Orange County Federation of Sportsmen’s Clubs. She is waiting to go out hunting until she can assess the fallout of the disease. “It’s just another case of 2020 strikes again,” she said.

Dr. David Stallknecht, a professor who studies the disease at the University of Georgia’s College of Veterinary Medicine, said New York is on the leading edge of this disease. “We’ve been getting reports from a more northerly direction over the last 20 years,” he said. “It’s a new virus entering a completely naïve population, similar to what Covid is doing entering the human population.” In New York, most deer that get infected are expected to die, according to the DEC. Survivors become immune, but may have lingering effects, like developing cracks in their hooves or becoming emaciated in the winter. Unlike Covid, this virus is not contagious from deer to deer.

The first cases of the current outbreak were identified in deer carcasses in Putnam and Orange counties in late August. Outbreaks hit in late summer and early fall, when midges are abundant, and appear more likely to strike in drier years, said Rosenbach. But between temperature, wind, and rainfall, there are so many variables that only one thing is certain: there’s no predicting the next outbreak.

New York’s first EHD outbreak was in 2007 in Albany, Rensselaer, and Niagara counties, and the next cycle hit Rockland County in 2011. Since white-tailed deer live an average of only four-and-a-half years in the wild, few if any deer living here today are old enough to have immunity from the last bout.

The viral strain we’re seeing now in New York – EHDV-6 – first showed up in the United States in 2006, when it was isolated in Indiana and Illinois, said Stallknecht. Now it’s all over the south, where antibodies are passed from doe to fawn, tempering the flare-ups that occur every three years or so.

In New York’s “naïve population,” however, the virus could thin the herd significantly, by 20 to 30 percent, said Stallknecht – though he cautions that such population-scale predictions are a weak spot in epidemiology. “But deer herds really build quickly,” he said, “so they’ll be back.”

At the start of bowhunting season, the DEC had no plans to reduce the deer hunt because of the virus. “Deer populations throughout the currently impacted region are robust,” the agency said in a press release.

NJ and PA spared

Nationwide, this has not been a particularly bad season for EHD, said Stallknecht. Though carcasses are turning up as far west as Warwick, the outbreak does not appear to have crossed state lines.

“At this time there is no known EHD in New Jersey I am aware of,” said Paul Tarlowe, a wildlife education specialist with the New Jersey Department of Fish & Wildlife. The department has asked outdoorspeople to report any sick deer sightings. New Jersey has suffered seven EHD outbreaks since 1955, and had its first documented case of the related Bluetongue Virus in 2014.

Pennsylvania had just one case of EHD this September, from a deer in a captive facility in Crawford County in the northwest part of the state, according to the Pennsylvania Department of Agriculture. “We’re kind of on heightened alert since these confirmed cases were so close to Pike County,” said Bill Williams, Northeast Region Supervisor of the Pennsylvania Game Commission.

The northward creep of the virus is widely attributed to climate change, said Stallknecht. Milder weather allows midges to live and breed longer, and creates the conditions for the virus to replicate more efficiently. The virus can infect other hooved animals like cows, sheep, and goats, which might get mild symptoms like hoof or mouth legions, he said. But only in white-tailed deer does it cause mass die-offs.

Whether deer will build up immunity here, or the disease will go back underground, or the virus will linger for years, is anyone’s guess. No one knows how long it took southern deer to achieve herd immunity. Stallknecht was just looking at data from West Virginia, where in two decades they have gone from hardly any cases in a year to almost every county reporting some. Examining antibodies from deer, “what we see is herd immunity isn’t really building up that much,” he said.

How humans are affected

Why devote so much attention to a deer virus? Don’t we have plenty of our own worries in the virus department? Although humans don’t catch EHD, understanding why it’s spreading could inform and prepare us for the next human vector-born disease, said Stallknecht. And just because we don’t get infected doesn’t mean the carnage won’t take a toll on us, too.

Watching the deer die a slow death was a morbid experience for Ridgeway, a vegetarian, nature-lover, and psychology student who’s about to start a job in a hospital neuroscience department. “It’s not pleasant,” she said. “Definitely watching a deer dying was pretty emotional.” As for the vultures endlessly circling her yard and the stench attracting her dog, it’s certainly putting a damper on her enjoyment of the outdoors – which for most of us is the saving grace of our quarantined lives.

The odor wafting up from wetlands and culverts can be downright depressing. “The stench of rotting carcasses is a constant reminder of how cruel Mother Nature can be at times,” said Brian O’Carroll of Florida, N.Y., an equipment operator and landscaper who has been hunting deer for 20 years. Each time he catches a whiff, “it rings in a sadness with me and all avid sportsman who have the utmost respect for the species we pursue each fall.”

White-tailed deer are a real resource around here, and hunters who rely on venison to feed their families are worried. “I fear for future hunting seasons,” said Kafka, who likes giving venison to co-workers. “The population has really taken a hit this year. I don’t buy meat from the grocery store. We only eat what I harvest, so it really has me nervous for next year that there won’t be as many tags given out.”

A hard frost or two will kill the midges that spread the disease, and for hunters, that can’t come too soon. In the meantime, it may take some creativity to salvage this hunting season. Locals like O’Carroll might have to abandon their “go-to deer spots and honey holes,” and try their luck in unfamiliar hunting grounds. “I will be scrambling to find suitable bucks to pursue with bow and arrow,” he said.

“Needless to say this deer season will match the rest of the strange year of 2020 and be somewhat of an unknown,” said O’Carroll. “For now, we can pray for and welcome a few frigid frosty mornings.”