Three dogs with dirofilariasis had a dermatologic syndrome, characterized by pruritus and multifocal nodules which tended to ulcerate. The cutaneous nodules revealed angiocentric pyogranulomatous inflammation with variable numbers of eosinophils. Microfilariae were often present in the blood vessels surrounded by the pyogranulomatous process. Therapy for dirofilariasis resulted in complete resolution of the dermatitis.