1. Departments of Clinical Sciences (Dehard, Bernaerts, Peeters, McEntee, Clercx) and Quantitative Genetics (Detilleux), Faculty of Veterinary Medicine, University of Liège, Liège, 4000 Belgium; and the
2. Department of Pathology and Microbiology (Day), Faculty of Veterinary Medicine, University of Bristol, Langford House, Langford, North Somerset, United Kingdom BS40 5DU
3. From the