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.

Detecção de Theileria equi e Babesia caballi e anticorpos anti-Ehrlichia spp. em equídeos do Pantanal Mato-Grossense, Brasil

“…(Wise et al, 2013). A piroplasmose se manifesta clinicamente desde uma forma aguda, em que os animais apresentam anemia hemolítica aguda, formação de trombos e coagulação intravascular http://dx…”

“…microplus são associados à transmissão dos protozoários Babesia caballi e Theileria equi, agentes etiológicos da piroplasmose equina (Wise et al, 2013). A piroplasmose se manifesta clinicamente desde uma forma aguda, em que os animais apresentam anemia hemolítica aguda, formação de trombos e coagulação intravascular disseminada seguida de morte, até uma forma crônica, em que são apresentados sinais inespecíficos que incluem letargia, anorexia e perda de peso (Wise et al, 2013).…”

Problems in the Protection of Reintroduced Przewalski's Horses (Equus ferus przewalskii) Caused by Piroplasmosis

“…Unfortunately, takhi became extinct in the wild from the pressures of hunting and pasturing of livestock in the 1960s. In 1992, takhi were transported from European zoos back to southwest and central Mongolia (Boyd and Bandi 2002 Theileria equi (formerly Babesia equi) and Babesia caballi are hemoprotozoan parasites in equines and are transmitted by ticks (Wise et al 2013(Wise et al , 2014Scoles and Ueti 2015). During reintroduction at sites in Hustai National Park and Gobi B Strictly Protected Area, deaths of adult takhi occurred during their first spring from April to May (Walzer et al 2000).…”

“…Those yearlings were usually feverish (.40 C), with nasal discharge and signs of anemia such as whitened mucous membranes. Approximately 12-17 ticks infested each yearling, and the tick was identified as Dermacentor nuttalli, which is a vector for T. equi and B. caballi (Battsetseg et al 2001;Wise et al 2013). …”

Why the Donkey Did Not Go South: Disease as a Constraint on the Spread of Equus asinus into Southern Africa

“…Two infectious agents are responsible for the condition, Theileria equi and Babesia caballi. While usually occurring separately, they may also simultaneously coinfect the same animal, although infection with T. equi is more common than infection with B. caballi (Wise et al 2013). Both are piroplasmic protozoa of the same phylum (Apicomplexa) as Plasmodium, which causes malaria.…”