Dead deer are showing up near streams and ponds in Chester County, and state wildlife officials say a virus is to blame.

The Pennsylvania Game Commission confirmed an outbreak of Epizootic Hemorrhagic Disease, or EHD, in Chester County and specifically in East Bradford Township, according to a civic alert the township posted on Tuesday, Sept. 15. The township said it had received several reports of dead deer that did not appear to have been struck by vehicles and were often found near water.

East Bradford borders West Chester Borough, and the county-wide confirmation means deer in the West Chester and Goshens area could also be affected.

EHD does not infect people.

The disease is spread by the bite of a small midge, not from deer to deer. Infected deer can die within 8 to 36 hours. There is no treatment for EHD in wild deer.

The Game Commission received confirmation at the end of July that seven deer had died from EHD in Chester County, GoErie.com reported Sept. 1. As of Aug. 31, that was the only confirmed EHD case in Pennsylvania for 2026, according to Game Commission wildlife biologist Jeannine Fleegle.

"Sick deer are often found near water sources. And this is because they are losing fluid because of leaky blood vessels and they're running a fever because they are infected with a virus," Fleegle told GoErie.com in late August.

The outbreak comes during a prolonged dry spell. Chester County has been under a drought warning from the Pennsylvania Department of Environmental Protection since at least June, according to a county government alert. Dry conditions can concentrate deer at shrinking water sources where the midges that carry the virus are commonly found.

Chester County has dealt with EHD before. The Game Commission confirmed six EHD detections in the county in 2024 and included Chester County among 14 confirmed incidents statewide in 2025.

The outbreak will continue until the first frost kills the midges. Fleegle told GoErie.com that frost is the only thing that ends new infections for the year.

Deer that survive EHD may later show signs of hoof overgrowth or cracks in their hooves, according to the East Bradford alert.

Residents who find a sick or dead deer that does not appear to have been hit by a vehicle should call Pennsylvania Game Commission Central Dispatch at 833-742-9453. Fleegle told GoErie.com that testing requires a fresh sample because deer decay quickly, so prompt reporting matters.