1. Department of Molecular Biomedical Sciences; College of Veterinary Medicine; NC State University; 1060 William Moore Drive Raleigh NC 27607 USA
2. Institute of Pharmacology, Toxicology and Pharmacy; University of Veterinary Medicine Hannover; Bünteweg 17 Hannover 30559 Germany
3. Bayer Animal Health GmbH; Leverkusen 51373 Germany