2015 ACVIM Forum Research Abstract Program

Six adult horses (8-25 years) and six 4 month old pony foals and their dams were used in the study. Both horses and foals were vaccinated with a commercially available combination vaccine (Vetera Ò Gold, Boehringer Ingelheim Vetmedica, St. Joseph, MO, USA) containing killed WN and EEE antigens. Adult horses and dams of the ponies had a previous history of yearly vaccination, whereas the pony foals had not been previously vaccinated. Blood samples were collected from the jugular vein of the horses, dams and foals on Days 0 (prior to vaccination), 7, 14, and 21 days after the 1st vaccination. On day 21, foals were given a booster vaccination and additional blood samples were obtained days 7, 14 and 21 post booster vaccination. In addition, blood samples were obtained from the dams of the foals at the same times and were used as sentinels for virus exposure, as the foals and dams were housed together in a pasture at the Louisiana State University Veterinary Sciences Farm. Blood samples were centrifuged and serum collected and frozen at À80°C until shipment. Serologic assays for WN and EEE, including IgM antibody capture ELISA (MAC-ELISA) and Plaque Reduction Neutralization Assay (PRNT), were performed at the National Veterinary Services Laboratory (NVSL) in Ames, IA, USA.