1. Department of Pathology, Bacteriology and Avian Diseases; Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 B-9820 Merelbeke Belgium
2. Department of Veterinary Public Health and Food Safety; Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 B-9820 Merelbeke Belgium
3. Nematology Unit; Department of Biology; Ghent University; K.L. Ledeganckstraat 55 9000 Ghent Belgium