1. Institute of Veterinary Pathology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
2. Institute for Veterinary Epidemiology and Biostatistics, Freie Universität Berlin, 14163 Berlin, Germany
3. Department of Anatomic Pathology, The Schwarzman Animal Medical Center, New York, NY 10065, USA
4. Veterinary Diagnostic Laboratory, Michigan State University, Lansing, MI 48910, USA