1. Department of Veterinary Science and Public Health; University of Milan; Milan Italy
2. Department of Microbiology; Immunology and Pathology, Colorado State University; Fort Collins Colorado
3. Immune Regulation Laboratory; Department of Clinical Science and Services; Royal Veterinary College; London United Kingdom
4. Department of Veterinary Sciences; University of Turin; Turin Italy
5. Clinical Pathology; Department of Pathobiology; University of Veterinary Medicine Vienna; Austria
6. Department of Pathology; Microbiology, and Immunology, School of Veterinary Medicine, University of California-Davis; Davis California