You hear it all the time from veterinarians- you MUST spay (or neuter) your cats. In order to adequately broach this topic, I will focus on female cats only. In a later blog post, I will discuss the importance of neutering male cats.
What is a spay?
The surgery we perform in female cats is called an ovariohysterectomy, colloquially known as a spay. This surgery involved removing the ovaries and uterus from cats so they cannot reproduce. Some facilities perform a surgery called an ovariectomy which involves only removing the ovaries. However, in the United States, ovariohysterectomies are much more common.
Your cat will be under general anesthesia for the duration of the procedure and be on pain medications for the days following. A spay is a serious surgery and requires an abdominal incision to visualize the ovaries and uterus. It is important to ensure your cat has a quiet, isolated place to recover in your home and keep activity level to a minimum after the surgery. Your cat should be separated from other animals in your home and not allowed to lick at the incision site. Cats tend to recover extraordinarily well following a spay if you follow your veterinarian’s instructions during the recovery period.
The major indications for this procedure are as follows:
- Population Control
- Prevention of mammary cancer
- Treatment of uterine/ovarian disease
- Hormone level modification
Let’s break each of these down further.
1. Population control
This is the most common reason we encourage owners to spay their female cats. This is the easiest way to control the population, especially in feral cats. You have probably heard of Trap-Neuter-Release programs. This involves capturing stray cats, sterilizing them, and then releasing them back where you captured them. Although it sounds kind of gruesome, feral cat colonies can be detrimental to wildlife in the area. Feral cat colonies are reservoirs for diseases that can impact domestic cats that occasionally go outside.
Additionally, there are about 1.6 million cats in shelters across the United States. Population control is essential to decreasing this number. Adult cats are much more difficult to adopt out than adult dogs. Many cats will spend their lives in shelters, or be euthanized. Spaying and neutering cats play an essential role in the prevention of overcrowding in shelters. Even if you think you will keep your cat forever, your female cat may escape from your home. In this case, if you do not spay your cat, you may have an unexpected kitten surprise a few months later.
2. Prevention of mammary cancer
In my opinion, the prevention of mammary cancer is the number one reason why I suggest owners spay their female cats. Intact (non-spayed) female cats are seven times more likely to develop mammary cancer. Now when we say “cancer” in medicine, we mean abnormal cell growth. Abnormal cell growth could be malignant (spreading to multiple organ systems) or benign (localized to one area). Unlike female dogs, the majority of the tumors that develop in intact female cats are malignant (approximately 80-96%). If they develop this malignant cancer, the median survival time is less than 1 year. However, if you spay a female cat at less than six months of age, there is a 91% reduction in the risk of developing this cancer. If a cat is spayed at less than one year of age, there is an 86% reduction in risk.
3. Treatment of Uterine/Ovarian Disease
There are many diseases that occur in intact female cats, some of which can be life-threatening. These include cystic endometrial hyperplasia, pyometra, ovarian cancer, uterine cancer, and uterine rupture/torsion.
For discussion’s sake, I will focus on the disease process we most commonly see in an emergency setting – pyometra. Pyometra is an infection of the uterus that commonly occurs in intact female cats (and dogs). This condition can be fatal and can cause toxins from the bacteria in the uterus to leak into the blood, potentially leading to shock and death. The treatment for this condition is a spay, although the success rate is not 100%. If the pyometra is severe, she will require extensive medical treatment and potentially an extended hospital stay. The best way to prevent pyometra is by spaying your female cat.
4. Hormone level modification
There are benign growths that develop because of hormonal influence in female cats. One common type is called fibroadenomatous mammary hyperplasia. This primarily affects young, intact female cats and may results in loss of blood supply to the area, ulcers, or tissue death. By removing the ovaries and uterus, you remove the female hormones associated with the abnormal tissue development seen in this condition. The treatment and prevention of this disease are the same: a spay.

Complications of spays
No surgery is without risks, including spays. The most common complications include hemorrhage (commonly associated with nicking a blood vessel during the surgery), stump pyometra (leaving part of the uterus in the abdomen), ovarian remnant syndrome (leaving part of the ovary in the abdomen), wound healing complications (infection, incision opening due to licking or activity, etc.), bowel obstruction, and acquired urinary incontinence. There are also risks whenever you put an animal under general anesthesia. If you are concerned with these complications, I encourage you to talk to your primary care veterinarian.

IN Summary
Unless you a cat breeder, veterinarians will typically recommend spaying female cats. Spaying not only contributes to population control but also reduces your cat’s risk of developing life-threatening diseases.
Do you have any questions about cat spays? Let me know in the comments below.