1. Department of Animal Pathology University of Zaragoza Zaragoza Spain
2. Institute of Veterinary Pathology Vetsuisse Faculty University of Zurich Zurich Switzerland
3. Sociedad Cooperativa Limitada Agropecuaria del Sobrarbe (SCLAS) Veterinary Service Huesca Spain
4. Institute of Virology and Immunology Bern Switzerland
5. Department of Infectious Diseases and Pathobiology Vetsuisse Faculty University of Bern Switzerland
6. Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2) Universidad de Zaragoza Zaragoza Spain