MEDFORD, Ore. — Black-tailed deer are turning up dead in several rural Jackson County communities in what wildlife officials believe is a new outbreak of a deadly disease that last decimated area herds more than a decade ago.
Biologists Tuesday learned they had their first confirmed case of the naturally occurring adenovirus from a deer found dead last week off Griffin Lane, but several reports of similar deaths have come in recently in Jacksonville, Eagle Point and elsewhere.
The deaths are occurring at a rate not seen since 2002, when more than 1,000 blacktails were estimated to die that summer and fall, according to the Oregon Department of Fish and Wildlife.
"We've had deer die in the past 10 years that we thought were from adenovirus, but now we're seeing a lot of dead deer," said Mark Vargas, the ODFW's Rogue District wildlife biologist in Central Point.
"We know it's here and now we know we have another outbreak," Vargas said.
As in past outbreaks, most of the dead blacktails so far have been found among urban deer or those living near rural residences, he said.
The virus is naturally occurring and outbreaks tend to happen during hot and dry months, Vargas said. It is also associated with people leaving food and water for animals, which causes unnatural congregations of blacktails and other animals.
Infected deer can suffer from bloody diarrhea that can scour the animal or mouth lesions that keep it from feeding. In some cases, the deer suffer massive internal hemorrhaging discovered only in field necropsies. In other cases, field necropsies revealed a liter or more of liquid in their lungs.
Humans and pets aren't considered vulnerable to the virus. While the adenovirus has similar strains affecting cattle and sheep, there are no known instances of the virus spreading from deer to other species.