Complex dermatitis is dermatitis caused by a combination of infections from various things such as fungi, ectoparasites, bacteria and congenital diseases simultaneously to cause clinical signs in the form of a combination of primary and secondary lesions. This case describes complex dermatitis caused by a combined infection of Sarcoptes scabiei, Demodex sp and Malassezia sp simultaneously. A mixed breed dog named Baby, 1.5 years old female, was brought in with complaints of itching, erythema, hair loss and alopecia since 1 month ago after being prohibited from mating by the owner. Clinical examination showed primary and secondary lesions scattered throughout the body. Investigations such as skin scraping and skin tape (Sitology) show an infection from the ectoparasite Demodex sp. Sarcoptes scabiei, and Malassezia sp. Causative therapy in the form of giving ivermectin (400 mcg/kgBB) and bathing therapy with sulfur shampoo was carried out in addition to supportive therapy to improve the dog's condition. On the 14th day after therapy, the dog's condition was reported to have improved and fine hair began to grow. The conclusion of this case, complex dermatitis that occurs in case dogs is caused by infection with Demodex sp, Sarcoptes scabiei, and Malassezia sp. in which the therapy given in the form of causative and supportive therapy was quite effective because the dog began to show improvement in its condition after 14 days post-therapy. The advice given in this case is that it is necessary to separate sick dogs from healthy dogs, improve feed for skin, maintaining the condition of the dog so that it’s not easily stressed and providing routine therapy as recommended by the doctor.