Merck Prestige 3 + WNV is an adjuvanted, tissue culture–origin equine vaccine in suspension for horses. Each 1 mL dose contains inactivated Eastern and Western equine encephalomyelitis viruses, a West Nile virus flavivirus chimera, and tetanus toxoid. Available as a 10 x 1 mL pack of prefilled syringes or a 10 mL vial for flexible barn or clinic use. A practical choice for horse owners seeking livestock health products and equine health products with convenient intramuscular administration.