1. Department of Clinical Sciences; College of Veterinary Medicine; NC State University; 1060 William Moore Drive Raleigh NC 27607 USA
2. Department of Veterinary Clinical Sciences; University of Minnesota; 1365 Gortner Avenue St. Paul MN 55108 USA
3. Clinic for Small Animal Internal Medicine; Dermatology Department; Vetsuisse Faculty; University of Zürich; Winterthurerstrasse 260 CH-8057 Zürich Switzerland
4. Comparative Medicine Institute; NC State University; Raleigh NC 27606 USA