1. SALUVET Research Group, Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Ciudad Universitaria s/n 28040 Madrid Spain
2. Viral Pathogenesis Department; Centro Nacional de Microbiología; Instituto de Salud Carlos III, Majadahonda; Madrid Spain
3. Animal Pathology Department; Faculty of Veterinary Sciences; University of Zaragoza; Zaragoza Spain