US: Wisconsin Confirms Epizootic Hemorrhagic Disease in Dairy Cattle

Wisconsin has confirmed epizootic hemorrhagic disease (EHD) in non-lactating dairy cattle in Waukesha County, marking the state’s first confirmed cattle case since 2013. The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) also reported EHD virus in wild and captive deer in the region.

EHD is caused by a virus transmitted primarily by biting midges, or “no-see-ums”, and typically becomes more active during late summer and early autumn. DATCP said new cases generally decline after the first significant frost.

Although clinical disease is generally less severe in cattle than in deer, affected cattle can show lameness, oral, teat or hoof lesions, excessive salivation, fever and weight loss. Importantly, some of these signs can resemble those of serious foreign animal diseases, making laboratory confirmation important.

DATCP recommends veterinary investigation and laboratory testing using appropriate blood or tissue samples when disease is suspected. There is currently no specific treatment for EHD, making vector management, herd health and early diagnosis central to control.

Strategic / Analyst View

The Wisconsin event illustrates the importance of vector-borne disease surveillance at the livestock–wildlife interface. EHD is not generally considered a major human-health threat, but its appearance in cattle provides an additional surveillance signal for vector activity and changing disease ecology.

For the animal-health industry, the opportunity set includes vector-control products, diagnostic testing, veterinary surveillance, wildlife monitoring and farm-level environmental intelligence.