A contagious disease characterized with severe pruritis, weight loss and alopecia was observed in laboratory mice in Experimental Animal Breeding Unit in University of Akdeniz, Turkey, after recently transferring the animals from Israel. Twenty out of 100 mice were referred to the clinics of the Department of Internal Medicine, Faculty of Veterinary Medicine University of Mehmet Akif Ersoy, for a diagnosis. Alopecia and severe itching were observed all over the body, particularly on the abdominal area. Skin scrapings were obtained from affected sites of the skin for a parasitological examination. At the examination of the skin scrapings, treated with 10% of potassium hydroxide, numerous mange agents and eggs were observed. Agents were diagnosed as Myocoptes musculinus according to their morphological characteristics. Five mice were euthanatized and examined pathologically. At the histopathological examination of the skin samples taken from alopecia and pruritic areas, numerous mange agents were seen in the tunnels in the epidermis. Mild inflammatory reaction including lymphocyte and neutrophil leukocytes were observed in the dermis. After diagnosis, mice were treated with ivermectin (Vilmectin) solution via drinking water (8 mg/L drinking water once a week for 3 wks). All animals were successfully recovered after the treatment.