1. Department of Veterinary Microbiology, Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria.
2. Department of Internal Diseases, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria.
3. Department of Diagnostics and Surveillance of Exotic Diseases, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise “G. Caporale,” Teramo, Italy.