Outbreak of EHD fatal to local deer

The mysterious deaths of a number of deer in Chester County has raised concerns among the deer hunting fraternity here in our neck of Penn’s Woods, but the mystery has apparently been solved. The culprit in this case was Hemorrhagic Disease (HD), a condition caused in white-tailed deer by either one of two closely related viruses, Epizootic Hemorrhagic Disease Virus (EHD) and Bluetongue Virus (BT). In this case it was EHD.

The EHD outbreak occurred here late last month and was investigated by Chester County’s Wildlife Conservation Officer Matt Johnson. “I was taken to a site by two hunters who had found six deer carcasses in East Nantmeal Township,” WCO Johnson reported. “They were in varying states of decay, from maybe ten days to one day. I could not see an obvious sign of death in any of them, as in trauma caused by a vehicle or firearm/crossbow.”

“I submitted the two freshest carcasses for testing and one of the two deer I submitted for testing a couple weeks ago has come back with a positive result for EHD. No other deer have been tested at this point,

but there have been two other reports in that area of deceased deer.” The evidence suggests that these other deer were likely also victims of EHD although test results on other carcasses were not available at this writing. WCO Johnson shared what is known about HD via the Pennsylvania Game Commission.

Hemorrhagic disease is one of the most common diseases of white-tailed deer in the eastern United States and can cause a significant number of deaths during outbreaks. The EHD and BT viruses are both transmitted by biting flies or midges in the group called Culicoides (Ku/lick/oyed/eez). Female midges pick up the viruses by ingesting the blood of an infected animal and they then transmit the viruses when they feed on an uninfected animal.

Midges are found near mud, which is their preferred breeding habitat,

so outbreaks usually occur when deer congregate in wet areas at the driest part of late summer and early fall when seasonal midge activity is also at its peak. They end when the first hard frosts take their toll on the midges and the virus dies with the insects.

The species of Cullicoides that is considered the primary vector of EHD is not thought to normally occur in Pennsylvania, but is occasionally brought into the state on wind currents. As a result, Pennsylvania deer do not have any immunity to the virus because outbreaks usually occur at intervals which are longer than the average deer’s lifespan. This lack of immunity explains the high mortality rates during EHD outbreaks in PA.

Clinical signs of hemorrhagic disease are all a result of the damage that the virus does to the walls of the blood vessels. They can range from sudden death to chronic disease. Whitetailed deer usually develop clinical signs of HD about 7 days following infection

with the EHD or BT virus, but some animals may remain asymptomatic. Clinical signs include swelling of the face or neck, loss of appetite, lethargy, weakness, lameness, respiratory distress, fever, and excessive salivation. Deer with HD will often have ulcers in the mouth and may bleed from the nose and/or mouth. Infected animals may develop swollen, blue tongues. They will also often experience hoof overgrowth and may have indentations or cracks in the walls of their hooves. Usually infected deer will go into shock and die within 8 to 36 hours of the onset of clinical signs. Necropsy of animals that die of HD will often reveal extensive hemorrhage from any or all internal organs. Organs more likely to exhibit hemorrhage include the heart, liver, kidneys, lungs, spleen, and intestines.

White-tailed deer and mule deer are the primary wildlife species affected by HD. This disease is occasionally associated with deaths of pronghorn antelope and bighorn sheep.

Elk can become infected with this disease, but they do not seem to be nearly as susceptible as whitetail deer. EHD rarely causes disease in domestic animals, while BT is a wellknown disease of sheep, cattle, and goats and can also infect domestic dogs. The viruses are not known to cause disease in humans.

“If EHD is what we’re seeing, we can expect some localized mortality,” WCO Johnson added, “but the insects carrying the disease will die with the first hard frost. Hunters who harvest a deer should take normal precautions when handling and preparing their deer. Otherwise, they should not be too concerned.”

YOUNG WATERFOWLERS PROGRAM

The Brandywine Red Clay Alliance is hosting their Young Waterfowlers Program for Teens, Ages 11-17, at the Ashland Nature Center in Hockessin Delaware on Wednesday

evenings from 7:00 to 9:00 p.m. over six sessions starting on Oct. 4. Participants may still register through the second week of the program and will learn wildlife management, conservation, decoy carving, waterfowl calling, safety skills, good sportsmanship, and much more. The program concludes with an optional hunt at the Bombay Hook National Wildlife Refuge. Cost for BRC members is $125. Online registration is available at www.brandywineredclay.org. For more info, call 610-793-1090.

WCFG&WA TALKIN’ TROUT

The folks at the West Chester Fish, Game, and Wildlife Association gear up for next spring’s trout season opener and will need some help to unload trout from the Pennsylvania Boat and Fish Commission truck when it arrives at the nursery on Wednesday, Oct.11, at 1:30 p.m. Nursery manager Mike Colley is looking for volunteers to help move the fish by buckets from the Fish Commission truck to their new home in the WCFG&W Nursery. “Bring gloves! Many hands will make for short work!” Colley added, “We are in need of volunteers to help feed the trout at the nursery located on Ravine Road. The time slots that we need to fill are Monday , Tuesday , Wednesday , Friday and Saturday afternoons . The commitment runs from mid Oct. to mid May. The feeding process only takes about ten minutes. If you are interested in filling a time slot or two, or can be an alternate, contact Colley at mcolley50@yahoo.com for information.”

OWL PROWL

The Brandywine Red Clay Alliance will hold an owl prowl on Oct. 23 from 7:00 to 8:30 p.m. for young, would be naturalists from ages 8 through 13 at the Myrick Conservation Center. On-line registration is available at www.brandywineredclay.org. For more info, call 610-793-1090.