What is a mammary tumor (breast cancer)?
A mammary tumor develops as a result of abnormal replication of the cells that make up the breast tissue. Mammary tumors can be benign (non-cancerous) or malignant (cancerous). These two forms of the disease have different diagnostics, treatments, management, and prognosis (see handout “Benign Mammary Tumors in Dogs” for information on the non-cancerous form of the disease).
There are several different types of malignant mammary tumors, with carcinomasbeing the most common. Carcinomas arise from epithelial (skin) cells, tubules of the mammary glands, or other cells found in the mammary chain.
There are other cancers that can affect mammary glands, including osteosarcomas (see handout “Osteosarcoma in Dogs” for further information on this type of cancer).