Plasvacc's equine blood products are collected from a USDA approved herd of approximately 90 horses. Prior to acceptance into the closed herd, the Department of Serology, UC Davis screens the animals for their suitability as plasma and red cell donors. Plasma donors must be free of agglutinins and hemolysins to common red cell antigens. Each donor must also test negative for antibodies to EIA, EVA, glanders, dourine, piroplasmosis and brucellosis. Donors are also screened for TDAV, antibody against the Non-Primate Hepacivirus (Equine Hepacivirus [EHCV]), Equine Parvovirus and Equine Pegivirus (EPgV). Once accepted into the herd, frequent serologic monitoring ensures continued freedom from disease.