Anne Lichtenwalner DVM Ph.D.: University of Maine Extension Elizabeth McEvoy DVM and Donald E. Hoenig VMD: Maine State Veterinarians Equine Piroplasmosis (EP) is a tick-borne disease of horses that may, in some cases, be fatal. Unfortunately, it is not preventable by vaccination. There are two protozoa (Babesia caballi and Theileria equi [formerly known as Babesia