Immunocidin® is recommended for the immunotherapy of mixed mammary tumour and mammary adenocarcinoma in dogs. Although Immunocidin® is administered by intratumoural injection, the response is generalized, and untreated sites frequently undergo regression. Prognosis should be guarded in advanced malignant disease with metastases, as remissions will be less frequent. Remissions cannot be guaranteed as each tumour will vary in its response.