title: Review of equine piroplasmosis.
abstract: Equine piroplasmosis is caused by one of 2 erythrocytic parasites Babesia caballi or Theileria equi. Although the genus of the latter remains controversial, the most recent designation, Theileria, is utilized in this review. Shared pathogenesis includes tick-borne transmission and erythrolysis leading to anemia as the primary clinical outcome. Although both parasites are able to persist indefinitely in their equid hosts, thus far, only B. caballi transmits across tick generations. Pathogenesis further diverges after transmission to equids in that B. caballi immediately infects erythrocytes, whereas T.equi infects peripheral blood mononuclear cells. The recent re-emergence of T.equi in the United States has increased awareness of these tick-borne pathogens, especially in terms of diagnosis and control. This review focuses in part on factors leading to the re-emergence of infection and disease of these globally important pathogens.
authors.affiliation: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA; Animal Disease Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Pullman, WA.
authors.forename: L N
authors.initials: LN
authors.lastname: Wise
authors.forename: L S
authors.initials: LS
authors.lastname: Kappmeyer
authors.forename: R H
authors.initials: RH
authors.lastname: Mealey
authors.forename: D P
authors.initials: DP
authors.lastname: Knowles
mesh_terms: D000818:Animals; D001403:Babesia / Q000254:growth & development*; D001404:Babesiosis / Q000097:blood / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*; D006734:Horse Diseases / Q000097:blood / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission; D006736:Horses; D015995:Prevalence; D016794:Theileria / Q000254:growth & development*; D013801:Theileriasis / Q000097:blood / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission; D013987:Ticks / Q000469:parasitology*; D014481:United States / Q000453:epidemiology
keywords: Anemia; Babesia caballi; Erythrocytic parasite; Theileria equi; Tick-transmitted