Ask Dr. Anna:

A few weeks ago our Relay for Life team raised over $4000.00 for the American Cancer Society.  Cancer is a common problem that we also see in pets, especially with them living longer.  This week I will discuss the third most common cancer in cats, which is mammary cancer.  Mammary tumors usually affect older female cats and Siamese and Oriental breeds are more predisposed.

Anna Coffin is the Veterinarian at Guthrie Pet Hospital and can be contacted at (405) 282-8796.

Hormones play a major role in mammary cancer development in dogs and cats.  Every heat cycle a pet goes through increases the chance of mammary cancer significantly.  One recent study proved that cats spayed before one year of age had a decreased risk of developing mammary cancer and intact female cats were seven times over-represented in the study.  Mammary cancer is far more malignant in cats than in dogs, so it is very important to remove the tumor as soon as possible.  In fact, 4 out of every 5 mammary tumors in cats are malignant and unfortunately 25% of cats diagnosed with mammary tumors have spread of the tumor to regional lymph nodes at the time of diagnosis.

Treatment involves early and aggressive surgical removal of all affected mammary glands.  Unfortunately, no studies have shown that chemotherapy extends survival time.  For most cats diagnosed with mammary cancer, prognosis is guarded.  The average time between detection and death is reported to be about one year.  Larger tumors are associated with shorter survival times.

Please e-mail me with your questions at [email protected] and put “Ask Dr. Anna” in the subject line or mail your questions to 123 West Harrison Guthrie, OK 73044.