[Theileria equi-infection in 2 German horses returning from a trail ride in southern France]. / Theileria equi-Infektion bei 2 Pferden nach einem Wanderritt in Südfrankreich.

Equine piroplasmosis, caused by the protozoan pathogens Theileria equi or Babesia caballi, is endemic in many (sub-)tropical regions worldwide, including Southern Europe. In Germany, it mainly plays a role as an imported parasitosis. Nevetherless, tick species with known vector potential for equine piroplasms occur in Germany. Thus, a long-term establishment of autochthonous cycles after introduction via infected equids or ticks cannot be excluded. In the present case, 2 horses developed clinical T. equi infection after returning from a trail riding trip to southern France. During treatment, a feeding tick was discovered on one of the horses, which was identified as a Rhipicephalus bursa specimen. This tick species cannot establish in Germany under the current climatic conditions; nevertheless, this discovery illustrates the potential of introducing infected ticks to Germany. The 2 horses were treated with imidocarb (3 mg/kg i. m.; 3 treatments in 3-day intervals) and no adverse drug effects were recorded. To prevent establishment of autochthonous infection cycles in Germany as well as a chronic manifestation of piroplasmosis, treatment should aim at eliminating the parasites despite possible adverse effects of imidocarb.