Wisconsin has confirmed epizootic hemorrhagic disease (EHD) in cattle in Waukesha County, the state’s first reported cattle detection since 2013. The detection comes as Wisconsin is experiencing a significant EHD outbreak in its white-tailed deer population.
The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) confirmed Sept. 29 that samples from non-lactating dairy cattle tested positive for the virus. EHD also has been detected in tissue from wild and captive deer in the region.
As of Sept. 28, the Wisconsin Department of Natural Resources (DNR) had received reports consistent with EHD involving just over 1,200 deer in Washington County and just over 400 in Waukesha County. Suspected cases also had been reported in Dodge, Fond du Lac, Jefferson, Milwaukee and Ozaukee counties. The DNR notes that these figures are based on reports of sick or dead deer and are not estimates of the total number of deer affected.
Wisconsin state veterinarian Dr. Darlene Konkle tells FOX6 that the affected cattle were young heifers raised on pasture.
“Cattle can also get this disease, but the clinical picture in cattle is usually much different. It’s much milder. In fact, we often don’t see clinical signs at all in cattle, but this particular group had some foot lesions, hoof lesions, and the owner worked with their veterinarian to get samples to Wisconsin Veterinary Diagnostic Laboratory, which is where we identified this virus,” she says.
EHD is caused by a virus transmitted by biting midges, also known as no-see-ums. The disease is most common in late summer and early fall when midge populations are higher, with new cases generally declining after the first significant frost.
Unlike white-tailed deer, cattle rarely develop clinical disease from EHD. When signs occur, they can include lameness, fever, weight loss, excessive salivation and sores affecting the limbs, mouth or teats. DATCP notes that oral, teat and hoof lesions can be difficult to distinguish from some foreign animal diseases without additional testing.
That diagnostic overlap makes veterinary involvement important when unusual lesions are observed. Veterinarians can submit blood, spleen, lung or lymph node samples for laboratory testing to differentiate EHD from diseases with similar clinical signs. If a foreign animal disease is also suspected, the case should be reported immediately to a DATCP district veterinarian.
The cattle detections indicate that EHD virus is circulating in the environment. DATCP recommends that herd owners work with their veterinarian to maintain overall herd health, with particular attention to flying-insect and parasite control, nutrition and avoiding overcrowding. There is no treatment for EHD.
EHD does not infect people. DATCP reports no evidence that humans are at risk from insect bites or from handling or consuming meat or milk from EHD-infected cattle or deer.
