Can Cats Get Breast Cancer? Learn About Mammary Tumors in Cats

What is a mammary tumor (breast cancer)?

A mammary tumor develops as a result of abnormal replication of the cells that make up the breast tissue. Mammary tumors can be benign (non-cancerous) or malignant (cancerous). These two forms of the disease have different diagnostics, treatments, management, and prognosis. In cats, the vast majority of mammary tumors are malignant.

There are several different types of mammary tumors, with carcinomas being the most common. Carcinomas often arise from the tubules of the mammary glands, or other cells found in the mammary chain.

There are several other kinds of cancers that can affect the mammary glands, including osteosarcomas.

What causes this cancer?

The exact causes for the development of mammary tumors in cats are not fully understood. However, exposure to the female reproductive hormones, estrogen and progesterone, increases the risk for mammary cancers in cats. It is hypothesized that under the influence of hormones, the cells of the mammary gland enlarge, progress to a pre-cancerous state, and continue to grow until they transform into a carcinoma.

The incidence of these tumors is related to hormone status, specifically whether a cat is intact or has had an ovariohysterectomy (i.e., has been spayed). Sexually intact cats have a 7-fold increased risk for mammary tumors compared to spayed cats. Early spaying helps to prevent the development of these tumors. Cats that are spayed before 6 months of age have only a 9% percent risk of developing mammary tumors, whereas the risk increases to 14% in cats spayed between 7 and 12 months. Male cats rarely develop mammary tumors.

Age and breed also play a role in tumor development. Mammary cancers are seen mainly in middle-aged to older cats (around 10 years of age). Siamese cats appear to be predisposed and are typically younger when diagnosed. Obesity may play a role in tumor development as well.

What are the signs that my cat has this type of tumor?

The most common clinical sign of a mammary tumor is one (or more) palpable masses (nodules) underneath the skin of the abdomen. They may be next to or within the nipple and follow along the mammary chain. The size of the mass(es) and their appearance may vary, but they are usually firm and nodular. Occasionally the skin over the mass may ulcerate (open) and bleed, and the affected area may feel warm to the touch and become painful. Your cat may tend to lick and groom the area excessively, and a strong odor can result as the exposed tissue becomes infected.

If the tumor has metastasized (spread to other areas of the body), other signs may become evident. Your cat may generally feel unwell, eat less, become lethargic, and lose weight. If the lungs are involved, your cat may have problems breathing or develop a cough.

Multiple tumors are common at the time of diagnosis.

How is this type of tumor diagnosed?

These tumors are typically found as either singular or multiple nodules along your cat’s abdomen during a physical exam. Other procedures are then performed to determine the type of tumor and whether it is benign or malignant.

A common procedure to diagnose this tumor is a fine needle aspiration (FNA). FNA involves taking a small needle with a syringe and suctioning a sample of cells directly from the tumor and placing them on a microscope slide. A veterinary pathologist then examines the slide under a microscope.

In some cases, results from FNA may not be entirely clear and removal of the entire tumor may be necessary. Pieces of the tumor are then examined by a veterinary pathologist under a microscope. This is called histopathology. Histopathology is not only helpful to make a diagnosis but can indicate whether it is benign or malignant, and therefore how the tumor is likely to behave.

Given the risk of metastasis (spread to other areas of the body) with malignant mammary tumors, your veterinarian may also recommend staging (searching for potential spread to other locations in the body). This may include bloodwork, urinalysis, X-rays of the lungs, and possibly an abdominal ultrasound. Lymph nodes associated with the mammary glands may be sampled by FNA even if they seem normal.

How does this cancer typically progress?

The way this cancer progresses is entirely dependent on the type and size of the tumor(s), and whether metastasis has occurred. Larger tumors (greater than 2 cm) and those with evidence of spread have a poor prognosis. If the histopathology report shows tumor cells invading the local blood vessels, this also carries a poor prognosis. Detecting and treating these tumors when they are small and prior to metastasis provides your cat with the best chance of long-term control. Tumors smaller than 2 cm carry the best prognosis.

What are the treatments for this type of tumor?

Surgery is by far the best treatment for cats with mammary tumors. Depending on whether there is a single mass present, or several masses a single chain mastectomy (removal of one side of the breast tissue) or double chain mastectomy (removal of both sides, with each mastectomy performed at a different time) will be performed. Depending on the tumor size and other factors, chemotherapy is typically pursued afterward, especially given the high metastatic rate in these tumors.

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Spring Weather Plays Havoc on a Cat's Hormonal System

Spring is right around the corner and with it brings an important consideration for your cat.

With spring comes longer days. The sun comes up earlier and stays up longer. And this increasing day length plays with a cat's hormones. The result is kittens; lots and lots of kittens.

Of course, kittens are cute and cuddly. Everybody loves kittens. But kittens grow up to be adult cats pretty quickly. Before long, kittens start making kittens of their own.

A female kitten can come into heat and become pregnant as early as 5-6 months of age. Male kittens generally become fertile about the same time as well. In addition, an intact female cat can become pregnant with a new litter while she is still nursing and caring for her previous litter. She can have several litters in the course of a year.

All in all, the reproductive cycle of the cat makes the species a pretty efficient breeding machine. That’s one of the reasons why spaying or neutering cats are so important. Spaying/neutering is the only effective way to control the cat population. So if you haven’t had your cat spayed or neutered yet, it’s time to think about getting that done.

Of course, there are other reasons also. Spayed or neutered cats make much better pets than those that are unaltered. Female cats are very vocal when they are in heat. Those that have considered breeding their female cats have changed their minds for this very reason. Living with a cat that is in heat is not a pleasant experience. (Not to mention the fact that breeding your cat solely for the purpose of making kittens without a well-planned breeding program in place is not a responsible action.)

The same can be said of male cats. Unaltered males have strong-smelling urine and can develop undesirable habits like urine spraying on everything and anything. Though spraying behavior can occur in altered males as well as in female cats, neutering your male cat definitely reduces the possibility of this behavior occurring.

There are also health benefits for altered cats. Female cats spayed prior to their first heat cycle have a significantly lower risk of mammary cancer later in life. The risk of a severe uterine infection known as pyometra is removed completely when your cat is spayed.

Remember also that your unspayed female cat can become pregnant if she lives in a household with an unaltered male, even if the male is related to her.

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5 Big Questions to Ask About Pet Obesity - How to Check, What to Feed, and How to Exercise

Obesity is becoming prevalent among pets that come through clinic doors. This is an incredibly critical issue because pets with obesity are at increased risk for developing serious weight-related disorders such as diabetes, arthritis, high blood pressure, kidney disease, cancer, and more. We must do better.

To help you better care for your furry loved one, here are the top five questions you need to ask your veterinarian to keep your pet healthy. They’re simple, won’t embarrass you, and just may save a life.

Question #1: Is my pet overweight?

This is the most important question you must ask your veterinarian – and one your vet may not be eager to answer. Unbelievably, many veterinarians are simply afraid to tell if your pet is overweight. This is primarily due to the fact your vet doesn’t want to inadvertently offend you. Weight issues are tricky and loaded with perceived judgment, strong emotions, and social stigmas.

As a concerned pet owner, you need to understand your pet’s weight is one of the most influential factors of longevity, quality of life, and disease prevention. To answer this question, your vet will conduct a couple of measurements, determine a Body Condition Score, and determine your pet's current weight status.

Ask the question. Demand a thorough assessment. Don’t be offended if the answer isn’t what you expected. This isn’t personal; it’s your pet’s future.

Question #2: How many calories should I feed my pet each day?

We’ve got to be specific when it comes to feeding our pets. Don’t fall into the trap of inquiring, “How much should I feed?” You’ll get a generic, inaccurate response. We need precise numbers of calories and nutrients your pet needs. That way, regardless of the type, brand, or formulation of food you feed, you can determine how much to feed. This is a subtle, but incredibly significant difference.

Your vet should then ask you a few lifestyle questions, perform a couple of calculations, and give you a narrow range of calories. Memorize this number. Find out how many cups or cans of your pet food this equals. Feed that amount. Don't forget to include any treats in your daily caloric counts. Those tiny “calorie grenades” can swiftly sabotage the best dietary plans.

Question #3: How much weight should my pet lose in a month?

If your pet is like most dogs and cats, it’ll need to shed a few unhealthy pounds of excess fat. You need to ask how much weight your pet needs to shed and how long will it take to reach a healthy weight. I prefer to think in terms of pounds per month due to practicality and performance. Monthly weight checks are practical and reasonable for even the busiest pet owners. A weight loss plan’s performance is critical to track and monitoring monthly trends is an accurate indicator of success or stagnation.

In general terms, a dog can safely lose 1 to 3-percent of its body weight and cats 0.5 to 2-percent per month. Many dogs can lose 3 to 5-percent and most cats should aim for about a half-pound per month. Losing weight isn’t easy or fast for pets, especially cats. If you put your pet on a crash diet, they can develop serious medical conditions, including a life-threatening form of liver failure that can occur in less than 72 hours. Patience is essential for pet weight loss. Most canine patients will have a 3 to 6-month weight loss plan and cats 9 to 12-months. Your vet will formulate a step-weight loss plan that will gradually decrease the amount you’re feeding over a 1 to 3-month period. This will help curtail cravings, begging, and late-night pestering. There will be some unhappy pooches and purr babies when you institute a diet. Your vet should provide you with tips on preventing these behaviors and transitioning to a new weight-loss diet.

Question #4: What kind of exercise should my pet do?

Most vets and pet owners focus on how long a pet should exercise each day. Instead, ask your vet what types of activities are best based on your pet’s species, breed, age, gender, current physical abilities, and interests.

Walking, swimming, agility, chase, ball retrieving, and remote-controlled toys – the opportunities for physical activity with your pet are endless. The general recommendation is that dogs need at least 30-minutes of physical activity a day and cats should strive for three 5-minute intense play periods. How you spend those minutes will determine if you do it or don’t. Make your outings enjoyable, entertaining, and interactive.
Cat owners, please don’t forget to ask this question. Whether you play with a feather duster or laser pointer, move the food bowl, or use a hip, high-tech toy, engage your cat’s inner predator and encourage it to pounce, leap, and prowl every day.

Did you know there are electronic gadgets that can monitor your pet's activity? They’re a great tool to document how much your pet is walking or playing each day. Better yet, you can share these reports with your vet to spot any deficiencies or ways to maximize your training.

Question #5: Is my pet at risk for a medical problem due to excess weight?

This is a profoundly serious question that you need to understand for your pet’s future. Dogs and cats carrying extra fat are at greater risk for developing debilitating diabetes, crippling arthritis, deadly high blood pressure, kidney disease, and many forms of catastrophic cancer. You need to have a frank conversation with your vet to find out if your pet is potentially facing one of these conditions. If so, what can you do to cut those odds? The most crucial decision you make each day about your pet’s health is what you choose to feed it. Choose wisely; your pet’s life depends on it.

It’s never too late to reduce your pet’s chances of contracting one of these grim disorders. Early recognition and awareness are the best defense against many diseases. Ask the question.

There are many more topics you need to discuss during your time with your veterinarian, but your pet’s weight should be covered at every exam. The few minutes you spend on diet and weight could well be the difference between two additional years of high-quality life or a shortened, suffering final stage of life. Take the time to write down these questions, ask your vet, and act on the answers. Together, you and your vet can chart a course for a better, longer, and happier life for your pet loved one. It’s worth it.

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