Thursday, October 9, 2014

Feline Mammary Cancer

October is Breast Cancer Awareness Month, and unfortunately, humans aren't the only ones who are affected by breast cancer.  Cats can suffer from mammary cancer as well.

Risk Factors & Symptoms

According to Cornell University College of Veterinary Medicine, mammary cancer occurs in female cats 95% of the time and is the third most common type of feline cancer, following lymphoma and skin cancer.  Mammary cancer is the most common type of cancer diagnosed in kitties over the age of 10.

Cats given the female hormones estrogen and progesterone for behavior modification or as a form of birth control are much more likely to get cancer than those who were not given hormones.  Additionally, Siamese cats seem to possess a genetic disposition for developing mammary cancer; they are twice as likely than other breeds to be affected by it.  Spaying a female before her first heat cycle decreases the risk of developing this type of cancer later in life.

There may be no noticeable lump or other symptoms in the earliest stage of feline mammary cancer.  In later stages, you or your veterinarian will be able to feel a lump under your cat's skin.  Some lumps can ulcerate the skin.  When this happens, many kitties will excessively groom or lick the ulceration, which can lead to infection.  Kitties with cancer may also experience fever, pain, and swelling.  It is not uncommon for a cat to have multiple mammary glands with cancer at one time.

Diagnosis & Treatment

If your veterinarian finds a lump in your kitty's mammary tissue, he or she will send tissue samples to a special laboratory for testing.  According to PetMD, approximately 85% of mammary tumors are malignant.  X-rays and abdominal ultrasound can be utilized to determine if a tumor has metastasized to surrounding lymph nodes, the lungs, adrenal gland, kidney, or liver.

Photo Credit: K B

The most common method of treatment for mammary cancer in cats is complete removal of the affected gland and associated lymph node.  A veterinarian may also choose to do a radical mastectomy where the entire mammary gland chain on one side is removed to prevent recurrence of tumors.  Chemotherapy may be combined with surgery if a tumor has metastasized to other parts of the body.


As with humans, early diagnosis and treatment of feline mammary cancer offers the best survival rates.  The removal of tumors smaller than two centimeters in diameter can offer a kitty three years or more of survival time.  

Always consult your veterinarian if you feel any unusual or new lumps under your cat's skin.  Early detection and treatment offer the best outcomes for surviving mammary cancer.  


  1. Yup, out Peep knows all about that darn breast cancer. It is very scary. But thanks for the good information. Hope very few kitties get that cancer. Take care.

  2. Cancer is a really tough one. My first pet - a dog- died from ovarian cancer. That was one of the toughest times in my life. Thank you for spreading the news.

  3. This is such an important post. Thank you for sharing this information. Cancer is a nasty thing to have.

  4. Pawppy had dogs in his childhood who died from various kinds of cancer.
    Us kitties here and our angel furblings have been spared this least as far as we know. Though there are plenty of other nasty ailments. Sheesh, so much misery to be watchfur fur and to be knowledgeable about.
    Meowmy herself has lost loved ones to cancer, and had her own bout with it too, in 2006. Praise the Lord, she has no evidence of it today. (Stage 3b Ovarian Ca)

  5. Pawesome post - we have a friend who lost her girlcat at a very young age to this - she was simply devastated.

  6. I am so glad I was spayed before I went into heat! That makes the possibility of my ever getting breast cancer very remote!

  7. I so wish I could have gotten Annabelle spayed before she gave birth.

  8. I had a TWitter furrend who was a feline breast cancer survivor. Great info.

  9. Thanks for the info. We didn't know much about Feline Mammary Cancer. It's important to spread awareness for diseases like this!