1. Institute for Animal Nutrition, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173 Hannover, Germany
2. Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, D-30559 Hannover, Germany
3. Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, D-30559 Hannover, Germany