1. Clinic for Small Animals, Faculty of Veterinary Medicine; Freie Universität Berlin; 14163 Berlin Germany
2. Comparative Tropical Medicine and Parasitoloy; Ludwig-Maximilians-Universität München; 80802 Munich Germany
3. National Center of Vector Entomology, Institute of Parasitology; University of Zurich; 8057 Zurich Switzerland
4. Parasite Consulting GmbH; CH-3006 Bern Switzerland