Canine demodicosis

Demodicosis is a common dermatologic disease in dogs and is especially prevalent in the southeastern and southwestern United States. Demodex canis is normally present in small numbers in canine hair follicles. Demodicosis is not contagious but results when a defect in cell-mediated immunity allows the mites to proliferate. The diagnosis is made by identifying a large number of mites in several skin scrapings. Approximately 90% of the cases of juvenile-onset demodicosis remit without treatment. Treatment is often prolonged and unsuccessful, and maintenance therapy is sometimes required to control the disease. Amitraz dips are the treatment of choice, but milbemycin oxime or ivermectin has been successful in amitraz-resistant cases. Because the defect that permits demodicosis to develop is inherited, no dog with any form of demodicosis should be bred.