In this chapter, the cutaneous metastases of non-primary skin neoplasms, namely, those originating from tumors of the internal organs, are discussed. Skin metastases of internal malignancies are very rare, and only sporadic cases of metastases from gastric, intestinal, prostatic, and bronchial carcinomas, from testicular seminoma, and from some sarcomas such as hemangiosarcomas and osteosarcomas have been reported in the veterinary literature. The spread of neoplastic cells occurs mainly via the bloodstream, and therefore, metastases can develop on any part of the skin. The most frequently observed cutaneous metastases are those linked to the bronchogenic carcinoma in cats, which characterize the so-called lung–digit syndrome. In this neoplasia, metastases are multicentric and mostly localized to the digits and less frequently can involve the skin. Although mammary tumors are off topic for this book, in dogs, as in human beings, a clinical variant of mammary neoplasia called inflammatory mammary carcinoma is well documented. This neoplasia is characterized by the lymphatic spread of neoplastic cells, which cause spread skin lesions that mimic other both neoplastic and non-neoplastic disease; for this reason, this variant of mammary neoplasia is discussed in this chapter.