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Title: Review of equine piroplasmosis

item Wise, Lauren
item Kappmeyer, Lowell
item MEALY, ROBERT - Washington State University
item Knowles Jr, Donald

Submitted to: Journal of Veterinary Internal Medicine
Publication Type: Research Technical Update
Publication Acceptance Date: 11/20/2013
Publication Date: 12/27/2013
Citation: Wise, L.N., Kappmeyer, L.S., Mealy, R.H., Knowles Jr, D.P. 2013. Review of equine piroplasmosis. Journal of Veterinary Internal Medicine. 27(6):1334-46.

Interpretive Summary: This invited paper represents a comprehensive literature review of the disease Equine Piroplasmosis and its causative agents Theileria equi and Babesia caballi. Treatments to eliminate persistent infection of horses with these parasites have been developed as well as diagnostics to show parasite elimination. These data are discussed in the context of this review.

Technical Abstract: Equine piroplasmosis is caused by one of two 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. While both parasites are able to persist indefinitely in their equid hosts, thus far only B. caballi transmits across tick generations. Pathogenesis further diverges following transmission to equids in that B. caballi immediately infects erythrocytes whereas T. equi infects peripheral blood mononuclear cells (PBMC). 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 will focus impart on factors leading to the re-emergence of infection and disease of these globally important pathogens.