Recent Cattle Reproductive Losses in NE Oregon: Epizootic Hemorrhagic Disease (EHD)

The Oregon Department of Agriculture (ODA) has recently received reports from veterinarians and cattle producers in Northeast Oregon about a concerning increase in late‑term abortions and the birth of dummy calves. Diagnostic testing has indicated Epizootic Hemorrhagic Disease (EHD) is present in fetal tissue in at least two of the reported cases.

What We Know So Far

• Reports are coming primarily from multiple counties in Northeast Oregon.
• Affected herds report grazing in Wallowa or Baker counties during the late summer or early fall.
• Clinical presentations appear consistent across multiple operations, though case severity varies.
• Diagnostic samples from several herds are currently being evaluated at OVDL.
• The Oregon Department of Fish and Wildife (ODFW) confirmed EHD in whitetail and mule dear mortalities in Wallowa and Baker counties during the late summer and early fall this year.

Veterinarians: What to Do if You Suspect EHD

EHD is an immediately reportable diseases in Oregon. If veterinarians suspect EHD, please report the case to ODA at 503-986-4711. Diagnostic testing is available at the Oregon Veterinary Diagnostic Laboratory. Ante-mortem samples include EDTA blood (ensure blood is well mixed in tube) while post-mortem samples include fresh vascularized fetal tissues (spleen, liver, kidney, heart, rumen, etc).

ODA is currently working with veterinarians of affected herds and partner agencies to investigate reported cases and determine the extend of impacted herds.
About Epizootic Hemorrhagic Disease (EHD)

Epizootic Hemorrhagic Disease (EHD) is a viral illness spread by biting midges that primarily affects wild ruminants but can also infect cattle. Most cattle show mild or no signs, though some may develop fever, oral lesions, lameness, or respiratory discomfort. Infected pregnant cattle may experience reproductive impacts, including early embryonic loss, decreased fertility, or, less commonly, abortion and neurological defects in calves or “dummy calves”.

Because there is no specific treatment and prevention for EHD, livestock management focuses on supportive care and reducing exposure to biting midges during late summer and fall. Vector‑control strategies, insect‑repellent applications, and careful observation of susceptible animals (mule and whitetail deer) help reduce disease impact. While cattle generally recover, reproductive losses and temporary declines in performance make prevention and surveillance important for herd health.

Source: ODA