Cover Your Bases: Test for EHD and Bluetongue

August 21, 2024

Hemorrhagic disease in deer can be caused by either Epizootic Hemorrhagic disease (EHD) viruses or Bluetongue viruses (BT). If hemorrhagic disease is suspected, the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) advises to test for both EHD and BT viruses.

Why does TVMDL recommend testing for both diseases?

  • Clinical signs and histological lesions are indistinguishable between EHD and BT
  • PCR negative EHD may still be BT positive, and vice-versa
  • Some animals may be positive for both EHD and BT

Correct diagnosis is the only way to ensure herd health, whether cattle or deer, and stem a potentially catastrophic outbreak. Utilize the following tests to rule out EHD and BT.

Bluetongue and Epizootic Hemorrhagic Disease Virus Multiplex (rtPCR)
Acceptable specimens: 1-2 mL whole, unclotted blood in an EDTA tube, 1 gram tissues (spleen), or 1-2 mL semen
Turnaround: Performed in College Station Tuesday-Friday, with results in 1-4 business days.

Bluetongue Virus (rtPCR)
Acceptable specimens: 1-2 mL whole, unclotted blood in an EDTA tube, 1 gram tissues (spleen), or 1-2 mL semen
Turnaround: Performed in College Station Tuesday-Friday, with results in 1-4 business days.

Epizootic Hemorrhagic Disease Virus (rtPCR)
Acceptable specimens: 1-2 mL whole, unclotted blood in an EDTA tube, 1 gram tissues (spleen), or 1-2 mL semen
Turnaround: Performed in College Station Tuesday-Friday, with results in 1-4 business days.

Bluetongue Virus Isolation (Egg Inoculation)
Acceptable specimens: 2-5 mL EDTA whole or heparin whole blood, 0.5-1 mL semen, 2-5 g spleen or other fresh tissues as deemed appropriate by submitter and/or professional staff.
Turnaround: Performed in College Station on Thursdays with results 7-21 business days.

Epizootic Hemorrhagic Disease Virus Isolation (Cell Culture)
Acceptable specimens: 2-5 mL heparin whole blood, 0.5-1 mL semen, 2 g spleen,  2-5 g fresh tissues as deemed appropriate by submitter and/or professional staff.
Turnaround: Performed in College Station on Tuesday with results in 14- 21 business days.