Breast Cancer in Dogs and Cats

By Expert Contributor Sarah Alexander, DVM, of The Spayed Club Clinic

Did you know that not only is breast cancer one of the most common types of cancer seen in women in the U.S. but that this disease can also affect your pets?

Mammary tumors, or neoplasias, are actually a fairly common disease process found in dogs and cats. Neoplasia is the doctor word for uncontrolled, abnormal growth of cells or tissues in the body. Just as in humans, a neoplasm or tumor in your pet can be either benign or malignant.

A malignant tumor is a neoplasm that has the potential to spread, or metastasize, to other parts of the body, affecting other organs such as the lungs or the liver. A malignant neoplasm is what we refer to as cancer. Neoplasia can develop from virtually any type of cell or tissue in the body. Tumors of the mammary tissue are a common type of neoplasia, both in humans and in dogs and cats.

Those at the greatest risk of developing mammary neoplasia are older, intact (non-spayed) females, though it is also possible in males. Mammary neoplasia is the third most common type of cancer in cats, and is 1 of the top 10 cancers found in dogs. The bad news for cats is that around 90% of mammary tumors in that species are malignant or cancerous. Dogs have a better prognosis, with only 50% being malignant and likely to spread to other organs.

Because exposure to female reproductive hormones like estrogen and progesterone predispose animals to the development of mammary neoplasia, intact females are more at risk of developing mammary tumors, especially as they age. Each heat cycle that an animal goes through increases that risk. Dogs spayed before their first heat cycle have only a 0.5% risk of developing breast cancer later in life. The risk increases with each estrus cycle, with an 8% risk after their first cycle then increasing to a risk of 26% after their second. Cats spayed before 6 months of age are 11 times less likely to develop breast cancer when they get older.

So what can you do for your pet to prevent this potentially fatal disease? Spay your dogs and cats early. Talk with your veterinarian about when to spay your pets in order to keep them healthy and at lower risk for such diseases.

The Mission of The Spayed Club Clinic: Eliminate unnecessary dog and cat euthanasia through affordable veterinary care and spay/neuter surgeries.

484-540-8436

800 Chester Pike, Sharon Hill, PA 19079

Veterinary Examination for Dog or Cat – $40. See our website for a list of services and transparent pricing.

www.TheSpayedClubClinic.org