William Oldenhoff, DVM, DACVD, is the staff dermatologist at ACCESS Specialty Animal Hospital in San Fernando Valley, California. Dr. Oldenhoff earned his DVM from University of Wisconsin–Madison, where he also completed a dermatology internship and residency. He has lectured worldwide, published numerous peer-reviewed articles, and contributed to several book chapters. His clinical interests are in recurrent pyoderma, Malassezia spp dermatitis, and allergy.