Equine Piroplasmosis (EP) is a blood-borne parasitic disease primarily transmitted to horses by ticks or contaminated needles. The disease was eradicated from the United States in the 1980ís, but it has recently re-emerged with a limited number of cases diagnosed in the US. This disease is not directly contagious from one horse to another but requires direct blood transfer. Human infection with equine piroplasmosis is extremely rare.
Acutely affected horses can have depression, fever, anemia (decreased red blood cells) jaundiced (yellow) mucous membranes and low platelet counts. EP can also cause horses to have roughened hair coats, constipation, and colic. In its milder form, the disease causes horses to appear weak and show lack of appetite. Some horses become chronic carriers of the disease.