The international clinical guideline for canine atopic dermatitis (CAD) was published by the International Committee on Allergic Diseases of Animals in 2015. Unfortunately, it does not fully cover the situations in Japan due to differences in veterinary practice between Japan and the rest of world. The Guideline Committee of the Japanese Society of Veterinary Dermatology (JSVD) attempted to develop guidelines for the diagnosis and treatment of CAD in 2016 and 2017, respectively. However, these attempts were unsuccessful because of a lack of clinical evidence. The most critical issues identified were the clarification of the clinical features of CAD among the breeds in which it commonly occurs in Japan, and the establishment of new methods for evaluating its severity. In particular, it is important to promote clinical studies supported by JSVD, in order to establish suitable biomarkers that can be used to objectively evaluate the therapeutic effect of treatments for CAD.