A male, 12-year-old Cairn terrier suffering from Cushing's syndrome with two therapy-resistant inflammatory subcutaneous lesions was examined pathomorphologically and parasitologically. Within the subcutaneous tissue, there was a suppurative to necrotizing and histiocytic inflammation present with the formation of caverns. Intralesional whitish-grey cysts with a diameter of 1-4 mm were detected. Molecular investigations of the cysts confirmed the preliminary morphological identification as Cysticercus longicollis. The adenohypophysis showed an infiltrative growing carcinoma. Cysticercus longicollis is the metacestode of Taenia (T.) crassiceps, a tapeworm of foxes and coyotes. Small rodents are typical intermediate hosts, in which the metacestode develops within the body cavities as well as in the subcutis. Subcutaneous cysticercosis after infection with eggs of T. crassiceps is also described in different domestic animal species and in humans, who represent aberrant intermediate hosts. Immunosuppression due to Cushing's syndrome, probably caused by the tumor of the adenohypophysis, may have played a role in the pathogenesis of the present case.