Pertaining to the breast.

of or relating to the milk-giving gland of the female

Relating to the mammary glands or breasts.

Cancer in the mammary glands is very common in dogs and cats. It is often hormone dependent from its initial development. Dogs and cats that are spayed early in life (less than one year of age) have almost no risk of developing malignant breast cancer. Approximately 50 percent of breast tumors in dogs are malignant and 90 percent in cats. Treatment is with surgery (mastectomy). The role of chemotherapy and radiation are undefined at this time. More than 50 percent of dogs are cured by surgery, whereas cat tumors are more malignant.

Having to do with the breast.

gland A gland present in female mammals that produces milk used to suckle the young. It probably evolved from a modified sweat gland and at least two are normally present, although in many mammals more than two are developed, usually concentrated on the underbelly beneath the pelvic girdle. In most mammals the size of the gland is determined by the state of the estrous cycle.