A 5-year-old Quarter Horse mare in Crow Wing County, was Minnesota’s first equine West Nile virus (WNV) case for 2003, according to the Minnesota Board of Animal Health (MBAH). Paul Anderson, MBAH assistant director, said the virus was expected to appear again this year, but not so early in the season. The first U.S. equine WNV case of 2003 was reported in Florida in early April.

The mare’s owner contacted his veterinarian on April 14 after the horse began acting abnormally. Clinical signs consistent with WNV emerged and worsened, and the mare was euthanized on April 19. Testing was completed at the University of Minnesota Veterinary Diagnostic Laboratory in St. Paul and confirmed at the Minnesota Department of Health Laboratory in Minneapolis. The horse received the first shot of the two-dose WNV vaccine series in April 2002, but never received the second shot or a booster vaccination. The mare was eight months pregnant when she died, and the fetus was lost