By
William Miller, VMD, DACVD, Professor of Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY
Craig Griffin, DVM, Animal Dermatology Clinic, San Diego, CA
Karen Campbell, DVM, MS, DAVCVIM, DACVD, Professor and Section Head, Specialty Medicine; Department of Veterinary Clinical Medicine, College of Veterinary
Medicine; University of Illinois at Urbana-Champaign, Urbana, IL