Ornithodoros ticks occur in the Mojave desert and frequently parasitize desert tortoises. These ticks carry the pathogen Borrelia, which is responsible for tick-borne relapsing fever. We aim to determine pathogen prevalence and species of ticks collected from tortoises to further understand infection kinetics of Borrelia in tortoises. Borrelia may cause disease in tortoises, but it's also possible there is an enzyme in tortoise blood that kills Borrelia.