Parasitic disease (Babesia) transmitted by the bite of a tick that lodges in the red blood cells of horses, causing tired and severe anemia. The clinical signs are frequently hyperthermia above 40 ° C and a lemon yellow coloring eye and oral mucosa of the animal with sometimes presence of small red spots. The horse also has a dark colored urine (hemoglobinuria) and signs of colic. In chronic forms a decreased appetite is observed, tired and weight loss of the horse. Definitive diagnosis is based on microscopic observation if a blood test several weeks after the crisis in order to avoid a false negative result.