Did You Know You'Re Risking Your Cat's Health By Not Spaying Her?

You've likely heard the lecture about cat overpopulation and the importance of spaying your cat. According to the ASPCA, about 3.4 million cats are brought to animal shelters in the U.S. each year. Of these, 41% are euthanized, often due to the fact that the shelter has no more room to house them. If that is not reason enough for you to spay your female cat, there are other important reasons—ones that directly affect your feline friend's health. Here are three of reasons that should convince you that spaying your kitty is the right choice.

Mammary Tumors

Tumors of the mammary glands are common in female cats, especially in unspayed cats older than 10. The definitive cause is unknown, but it's thought that there is a connection between mammary tumors and the hormones estrogen and progesterone. According to a report by the Cornell University College of Veterinary Medicine, administering these hormones for birth control purposes causes a dramatic increase in mammary cancer rates. Researchers at Cornell also report that spaying cats before their first heat, which can occur as early as 5 months of age, can decrease the incidence of mammary cancer by 91%.

Mammary gland tumors start as a small mass or nodule near the nipple or in the surrounding tissue. Approximately 85% of mammary tumors are malignant.  These tumors grow rapidly and can quickly spread to nearby lymph nodes and other organs such as the lungs, liver, and stomach. Owners of unspayed female cats should routinely examine them for lumps around the nipples because the sooner a malignancy is diagnosed and treated (typically by surgical means), the better the prognosis.


A female cat with an intact uterus is at risk for a condition called pyometra. Pyometra is Latin for pus-filled uterus. During a heat cycle, a cat's cervix opens to allow a male cat's sperm into the uterus to fertilize the eggs. This physical change can allow bacteria into the cervix. If the heat cycle does not result in a pregnancy, the cervix closes, trapping bacteria and blood in the uterus. This trapped bacteria can result in a uterus engorged with fluid and pus—pyometra. The bacteria and toxins from the infection can enter the bloodstream, causing life-threatening problems.

Symptoms of pyometra include lethargy, fever, lack of appetite and distended abdomen. Removal of the infected uterus offers the best survival chance for your kitty. The one sure-fire way to prevent pyometra is spaying, as without a uterus, a pyometra cannot occur.

Feline Immunodeficiency Virus

Feline Immunodeficiency Virus (FIV) is a virus that weakens a cat's immune system and makes them susceptible to other diseases. It is similar to human immunodeficiency virus (HIV), although humans cannot get FIV from cats. FIV-positive cats need to be monitored closely for other conditions because with a compromised immune response, they have few defenses against these diseases, and they can easily succumb to them.

FIV is transmitted through a bite from an FIV-infected cat. Stray or feral cats have a much higher incidence of FIV because they are more likely to get into cat fights. An unspayed female cat is at higher risk for contracting FIV because, during their heat cycle, they are more likely to attract and perhaps get into fights with male cats, and male cats typically bite the female on her neck during the mating process, which can transmit the virus to the female. The virus itself produces no symptoms, so only secondary diseases will alert you to the fact that something is wrong. There is a test to determine whether your cat is infected with FIV, but there is no cure. Spaying your female cat (and keeping her inside) can reduce the chances she will be infected with the disease.

For more information about the benefits of spaying, talk to clinics like Haverford Animal Hospital.