Equine Herpes Virus in Wisconsin

Equine Herpes Virus-1 (EHV-1)

EHV-1 can cause respiratory disease, abortions and occasionally neurological disease in horses as well. There are strain variants, one of which is more strongly associated with neurologic disease (neuroparalytic strain); however at least 25% of horses with neurologic disease do not have the neurologic strain.

Recently, horses in Minnesota and Wisconsin have developed hind limb paralysis and have tested positive by real time PCR for EHV-1. The WVDL offers a real time PCR for EHV-1, and it has the capability to differentiate between the wild type and the neurotropic strains of EHV-1. Veterinarians should submit nasal swabs that are placed in viral transport media or in 1 ml of sterile saline from acutely affected horses to the WVDL for testing. Samples should be sent over-night to the Madison laboratory with a sufficient number of ice-packs to keep the samples cold during shipment to the laboratory. Do not use cotton tipped swabs or swabs with wooden shafts because they contain bleach which may interfere with the PCR assay and cause a false negative test. Results are available within 1-3 business days after receipt of the samples. Veterinarians can order swabs and viral transport media from the WVDL. Please call 1-800-608-8387 and ask for the supply room.