There have been reports from equine practitioners in parts of eastern MN and western WI of horses with acute neurologic signs. Two of the affected horses have tested positive for equine herpesvirus-1 (EHV-1) infection (non-neuropathogenic strain). The two positive cases were horses on the same premises in Chisago County, Minnesota. Diagnostic tests are pending on additional horses.
Equine herpesvirus-1 is a highly contagious virus that causes respiratory disease, abortion, and intermittent outbreaks of neurologic disease in horses. Symptoms that should alert horse owners to the possibility of neurologic EHV-1 infection include fever, weakness and incoordination, and urine dribbling or inability to urinate. Horses with these symptoms should be examined immediately by a veterinarian. Suspect horses should be isolated from healthy horses and tested for EHV-1.
The neuropathogenic strain of EHV-1 is a reportable disease in Minnesota. Test results that are confirmed to be the neuropathogenic strain of EHV-1 must be forwarded to the Minnesota Board of Animal Health.
The University of Minnesota Center for Animal Health and Food Safety recommends that horses with a fever and symptoms of contagious respiratory infection should be kept at home and not taken to shows, clinics or public trail rides. Horse owners should also be aware that transportation of horses to competitions, shows and clinics may increase the risk of exposure to infectious organisms. Owners of affected horses should wash and disinfect their hands and change their clothes before coming into contact with healthy horses to prevent the potential spread of these infectious organisms.
The Minnesota Board of Animal Health will provide updates to the veterinary community as the situation evolves.
Educational handouts on EHV-1:
U of M Center for Animal Health and Food Safety EHV-1 fact sheet
http://www.cahfs.umn.edu/prod/
U.S. Department of Agriculture EHV brochure
http://www.aphis.usda.gov/vs/
