Breast cancer is an important medical concern for women, how common is it in pets?
The single greatest cause of breast cancer in pets is their heat cycle. The hormonal fluctuations, especially the increase in estrogen, that occurs during a heat cycle creates changes in the mammary tissue. These changes can lead to the formation of abnormal cells and eventually cancer.
Dogs have 10 mammary glands, 5 on each side, extending from the forward part of the chest all the way to the groin area. Cats have 8 glands, 4 on each side. That creates a lot of tissue that can be affected.
Spaying your pet greatly reduces the chances of developing breast cancer.
Age When Spayed Incidence of Breast Cancer
Less than 6 months Less than 1%
6 to 24 months Less than 25%
Greater than 24 months Greater than 50%
In those females spayed prior to their first heat cycle, breast cancer is very, very rare. Those that are spayed after their first heat but before 2 years of age will have a somewhat decreased incidence of breast cancer. Those spayed after 2 years of age have the same incidence of disease as those who were never spayed. Greater than 50% of non-spayed female pets will develop breast cancer.
If your pet gets breast cancer, what are the treatment options?
Surgery is the most common form of treatment. Radiation and chemotherapy can also be used depending upon the particular animal and the stage of the cancer. These treatments are expensive and stressful on the animal.
The best approach is prevention and spaying pets when they are young prevents breast cancer. If you have a pet that will not be used for breeding or showing, spay her before six months of age in order to prevent the first heat cycle and therefore prevent breast cancer.