Mammary Cancer
What is Mammary Cancer?
Also called breast cancer, mammary cancer is a tumor of the mammary glands. Tumors may be benign or malignant.
How does my dog get Mammary Cancer?
As with most cancers, the cause is not known. However, it is likely associated with hormonal influences. Some genes have been found to be overly expressed in dogs with mammary cancer, but the association is not strong enough to justify DNA testing. It occurs almost exclusively in females, and is seen more often in older dogs.
How do I know if my dog has Mammary Cancer?
Most owners first notice it as a lump in one or more mammary glands. The lumps may be firm; some may cause bleeding from the gland. Because the mammary glands may have lumps due to other causes, your veterinarian may wish to take a biopsy of the lump to confirm the diagnosis and determine the type of mammary cancer. Radiographs of the chest may be taken to make sure the cancer hasn't metastasized to the lungs. About half of all tumors are benign. The prognosis is worse for quickly growing tumors, larger tumors, deeply extending tumors, or bleeding tumors.
What can I do about Mammary Cancer?
It is never a good idea to leave a lump in place to see if it gets worse. The best treatment is surgical removal. If your female has not been spayed, spaying her at the time of the surgery may benefit the cancer response to treatement. Chemotherapy may be a part of the treatment plan.
Is there anything I can do to prevent my dog from getting Mammary Cancer?
Spaying a bitch before her first estrus (heat) reduces the chance of mammary cancer to almost zero; spaying before her second heat also greatly reduces the chance, to about 7 percent. Even spaying after the second heat reduces the chance significantly. After that, the chance of a female dog getting mammary cancer is about 25 percent.
Are there certain breeds that get Mammary Cancer more often?
All breeds are susceptible, but some believe Toy and Miniature Poodles, Springer Spaniels, Cocker Spaniels, English Setters, German Shepherds, Pointers, Maltese, Yorkshire Terriers, and Brittanys to be at higher risk.