Dermatitis is a nonspecific term usually used until the dermatologic history, clinical signs, and physical examination can more precisely define the problem. Dermatologic problems are a major category of clinical findings that can be caused by a number of skin diseases; many skin diseases look alike and are differentiated by working through diagnostic flow charts and a process of elimination. The most common dermatologic problems include pruritus, alopecia, crusting and scaling, otitis, nonhealing wounds, nodules and tumors, and ulcerative disorders. In some species, such as cats, there may be well-recognized subcategories of dermatologic problems (eg, head and neck pruritus, symmetric alopecia, eosinophilic exudation/dermatitis, etc). Defining the major dermatologic problem will help create a specific differential diagnosis list and aid selection of appropriate diagnostic tests. The animal’s dermatologic problem may or may not be the owner’s chief complaint. It is important to be sensitive to owners’ perceptions of problems or complaints, especially if odor or aesthetics are involved, and to address them (eg, bathing to minimize odor while the key problem is being evaluated).