Sunday, April 14, 2024
Daily Featurefeline breast cancerhealth and safety

Reduce Chances of Feline Mammary Cancer By Spaying Before First Heat


Rescued kitty Gracen lived nearly all her 10+ years owned but unspayed, living outdoors bearing kittens no one wanted. Finally rescued and spayed, in a couple of new homes then back to her rescuer, she was diagnosed with feline mammary cancer, common in an unspayed cat at that age. Even though it was found early, mammary cancer for cats is most often not survivable, and cats like Gracen who are spayed beyond two years of age are at highest risk of breast cancer. After surgery the cancer advanced again.

October is breast cancer awareness month, and that goes for our pets as well as humans. October 16 is Global Cat Day as well as Feral Cat Day, a category of cats who are often trapped and spayed after they’ve had a little of kittens and at high risk for this disease. Feline mammary cancer is the third most common cancer among cats after lymphoma and skin cancer. In a 2005 study done at the University of Pennsylvania, “cats spayed prior to 6 months had a 91% reduction…those spayed prior to one year had an 86% reduction in the risk of mammary carcinoma development compared with intact cats.” Spaying between one and two years of age only reduces the risk by 11%, and after two years it doesn’t reduce the risk at all. Actually giving birth to kittens doesn’t change the risk factors, either. The average age of diagnosis is 12 years, and certain breeds such as Siamese and Persian are more frequently diagnosed, and at an earlier age, than other cats.

While breast cancer in cats is more common than in humans, it is far less common than it is in dogs, but cats have the highest malignancy rate and the lowest survival rate of all three because about 90% of all tumors are malignant, vs. about 50% for dogs. Early detection and treatment is key to recovery and survival.

That myth that “it’s good to let a cat have a litter of kittens” has no basis in fact, and can be a death sentence since spaying your cat before it even goes into heat the first time is the best way to avoid breast cancer, not to mention reducing the risks of injury and disease a cat faces while out carousing. So, for Breast Cancer Awareness Month, we consider breast cancer in our cats.

Check those rescued mom cats

Poor Mimi doesn't even get a break to eat.
Poor Mimi doesn’t even get a break to eat.

Mimi, at left, arrived in my home on July 29, 2007, with four black fuzzballs who were three days into this existence. To my knowledge, she was about four years old and had had six litters of kittens. This litter would be her last.

I frequently give Mimi’s belly a little extra rub top to bottom, not because she likes it, but because I like her. I did with Kelly too, and she seemed to understand I wasn’t invading her privacy. Most of the cats I’ve lived with came to me as adults, most of the females unspayed, and back in the day, if we didn’t know whether or not a cat or kitten was spayed, we just waited until she went into heat to figure it out.

Kelly, too, was a rescued stray/feral and apparently gave birth to a few litters of little Kellies before she was rescued and spayed in a shelter. I was never certain of her age, but she was likely about 4 when she came to me in 1997. It took Kelly years to find a certain comfort level with people though she was very friendly, and the regular tummy exam was a little weird for her but she grew to enjoy it. I really didn’t know how old Cookie and Moses and Sophie were but with all three I waited until they went into heat to have them spayed as was recommended at the time. That’s been a lot of mammary glands to check, but so far no one has developed any mammary cancer. Sadly, a few of the adult female cats I’ve rescued and rehomed over the years have developed mammary cancer.

Those of us who have rescued cats or adopted cats who have borne even one litter would be wise to keep an eye open for symptoms and perform these regular breast exams on our cats, just as we should be doing on ourselves. I have long been aware of this with my girls, and during one yearly exam our veterinarian felt a little bit of a lump on one of Mimi’s mammary glands near the bottom of her belly. I’ve noticed it over the years too, and as Mimi grows older we’ll be paying closer attention to it, and to Mimi’s other mammary glands. Mimi was a little lumpy after so many litters to start with and went into heat again just a few weeks after the Four were born. Even after they were weaned and I’d separated them for several weeks she continued producing milk, some of which hardened in her mammary glands, so our monthly exams can be puzzling and frightening. The solution to that is to keep examining and getting to know your cat’s mammary glands better so that you notice changes. (I will note that I developed fibrocystic disease in my early 40s as did my mother, so my own monthlies can be kind of unsettling sometimes too, and that simply being familiar is of utmost importance.)

The monthly breast exam for your kitty

That overall monthly mini-exam is a good practice for any animal guardian to undertake, just running your hands over your cat’s body feeling for lumps or bumps or cuts or any abnormality that has simply shown up. Check for tender spots, look closely for any change in movement, study your cat’s eyes and even smell its breath. Of course, you may end up with your nose surgically removed since many cats don’t care for being handled in this way, especially in vulnerable areas like the belly, but do your best without too much bloodshed. For more information about a monthly mini-exam for your pet, read Help Your Pets to Stay Well which includes information on what to look for and a downloadable checklist for the exam.

And then for the girls, check for any changes in those eight mammary glands, which are usually completely symmetrical and slightly reducing in size from chest to hips. Look for changes in the nipples or any discharge, uneven lumps or swelling and tender spots. At least we humans only have two mammary glands to worry about.

And ladies, don’t forget yourselves!

The spay scar


When I started this exam routine years ago, I found a small lump on my Sally’s belly and made a special appointment with my veterinarian to get what I was sure was a horrifying diagnosis. I wrung my cold and trembling hands as my veterinarian felt the area of Sally’s belly I’d indicated, only to learn that it was scar tissue on her spay scar. I was too happy to be mortified at what a fool I seemed to be. So, get to know your kitty’s spay scar, which is usually tiny and often invisible but may contain a little hardened scar tissue, and it may also be a site of cancerous growth, so check for changes.

For more information on the disease and treatment, reference these two articles: Association between ovarihysterectomy and feline mammary carcinoma, and Mammary Cancer in Cats, as well as Mammary Tumors in Cats on the Manhattan Cat Specialists website.

For other information and to join with a community of feline mammary cancer survivors, visit Sugar’s website, Sugar Rub, and read her story of her human’s home exam, finding a lump, diagnosis, surgery and the whole process. Her human set up the website and a Sugar Rub Facebook page to spread awareness of feline mammary cancer and information about breast cancer exams, treatments and support. And Breast Cancer in Pets on the Halo website explains the monthly exam pretty thoroughly.

black cat with hard e-collar
Mimi wears her collar and hides her spay sutures.

When to spay, and early spay and neuter

It used to be that six months, the approximate age a cat reached sexual maturity, was the best time to spay a cat. There were two problems with this. First, cats often went into heat before this age to the surprise of their owners who thought Fluffy’s biological alarm clock wasn’t set for four months. Second, people wanted to adopt young kittens and were sent home with an assurance of a free or low-cost spay for Fluffy included in the cost of adoption. Somehow, Fluffy wouldn’t get back in time, sometimes never. In cat rescue, we see the results of this every single day.

Many shelters now spay and neuter cats when they reach two pounds, about eight to ten weeks, what I call the “two pounds or two months rule”, and they are not available for adoption until then. They recover quickly and are still cute kittens, frisky and full of fun, and no one needs to worry about their biological clocks.

Another common risk in unspayed cats

Aside from breast cancer, one other often fatal condition unspayed cats and dogs can develop is pyometra, wherein the uterus becomes infected and fills with pus, expanding to seem as if the cat is pregnant. If left untreated the cat becomes septic and the uterus can also burst, spreading the infection into the cat’s abdomen. We have had several unspayed female cats come into our rescue whose owners thought they were pregnant as their abdomen slowly expanded. Many were fortunately saved by timely surgery, but others did not survive.

Low cost spay programs at shelters in Pittsburgh and beyond

If you’ve taken in a stray or adopted a kitten who is not spayed or neutered, there’s no question that spaying or neutering is expensive. Here are a few options to help keep it affordable. A few programs have an application process with an income level that determines the final price of your cat’s surgery, others are simply a low flat rate. In many cases the surgery alone can be done for under $50.00.

For more clinics in Western Pennsylvania and a list that I regularly update, visit the Animal Assistance page on The Creative Cat.

Find Local Low-cost Spay, Neuter and Veterinary Care on the Internet

Low-cost Neuter and Spay (search by zip)

Love That Cat (online search)

Spay USA

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2 thoughts on “Reduce Chances of Feline Mammary Cancer By Spaying Before First Heat

  • I found this post both interesting and alarming, as I had no idea that this was the case. Thankfully we always spayed all our animals before their first heat, but I’m so glad you shared this post!

    • April, that’s wonderful to hear! I still meet people who think it’s best to let your cat have a litter, and vets who say to wait until 6 months. We in rescue still find many mom cats with kittens, and those are the ones I really worry about–they had no choice, someone abandoned them. But please pass it on whenever possible.


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