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Feline Cancer — Understanding Cat Cancer Symptoms, Research & Treatment

A cancer diagnosis is so difficult on so many levels.

When we heard the words ‘feline cancer’ as we stood at the vet office with Yoda, we felt powerless, confused, and stunned. It made taking in information difficult, as a sense of overwhelm washed over us. 

Yoda has now completed his treatment for Feline Injection Site Sarcoma Cancer (FISS), which you can read more about on our dedicated blog post linked above.

But we felt we’d like to continue our work in supporting owners facing a cat cancer diagnosis, by providing the kind of information we wish we had known before standing in that office.

Things like what are the common symptoms and how is cancer diagnosed in cats? What’s the latest feline cancer research and can cats survive cancer?

So in this post, we’ll be aiming to help you prepare for any future diagnosis, or cope with a current one. We are here to ease your stress and help you understand feline cancer in more depth, so you can feel prepared and in control. 

Quick facts:

  • Each year around 6 million new cancer diagnoses are made in cats.
  • Lymphoma, Mammary Cancer, Skin Cancer & Fibrosarcoma are the most common cancers in cats. 
  • Treatment usually involves surgery, chemotherapy and radiation.
  • Some research suggests herbal medicine could be helped to improve wellbeing, slow cancer growth and even induce remission in rodents. 
  • At the moment, the survival rate for cancer in cats is under 50%.
  • Much of the prevention research around cancer is similar to human cancer prevention advice. 

Let’s start at the very beginning. 

cat with three legs walking outdoors on harness and leash
Yoda after his amputation from FISS cancer

What Is Feline Cancer

Cancer is the name given to an abnormal growth of cells.

They grow uncontrollably, without receiving the instructions to do so. As they grow, these cells can mutate and change, resulting in negative effects to surrounding organs and tissues.

This is why we sometimes associate cancer with lumps or tumors, but this isn’t always the case. 

Is Cat Cancer Common?

​​There are around 32 million cats in the United States, and each year around 6 million new cancer diagnoses are made in cats. So cat cancer is fairly common and seems to be rising. 

However, it’s hard to judge this as many factors come into play. For example, more owners are recognizing cancer symptoms and diagnosis has improved too. 

Similar to humans, many veterinarians believe that cancer rates could also be rising because our pets now live much longer — well into their teens. As they are often so well cared for!

What Kinds of Cat Cancer Are There?

  • Lymphoma – Is a cancer of the white blood cells and the lymphoid tissue (like the lymph nodes for example.) The Feline Leukemia Virus (FeLV) was one of the leading causes of lymphoma in cats, until the development of a recent vaccine. 
  • Mammary Cancer – Also known as breast cancer, these tumors tend to develop in older cats. It is rare for male cats to be affected by this kind of cancer, and much more common in females. 
  • Skin Cancer – These tumors can appear as light or unpigmented skin and are usually a result of excess sun exposure (similar to humans.) These are often sighted around the nose, eyelids, and ears — the hairless areas. 
  • Fibrosarcoma – A tumor that develops from fibrous connective tissue. Some cats, like Yoda, can develop this at a prior vaccination or other injection sites. This cancer is aggressive, though the cat will usually show no pain around the tumor. 

How Is Cancer Diagnosed in Cats?

If your cat suspects cancer could be causing your kitty’s new mass, discomfort, or other symptoms, they will begin a series of steps towards diagnosis. This can include:

  • X-rays – Or other minor scans like ultrasound examination
  • Biopsy – Surgical removal of a small piece of affected tissue for analysis
  • Fine needle aspirate – This is what Yoda had, a small needle inserted into the mass to remove a few cells for further examination 
  • Needle biopsy – Here a larger needle is inserted into a lump to remove a very small ‘core’ of tissue
  • Blood samples – To detect any adverse effects of cancer or the presence of any other possible causes
  • CAT, CT, or MRI scans – These larger scale scans are less common, but thankfully becoming more widely available for pets, and help to assess tumor spread or the presence of brain tumors

If your cat has a tumor present, your vet will look to see if it has spread to other parts of the body. If it has not spread, then it’s usually called a ‘benign’ tumor.

A cancer diagnosis is used when the tumor has spread — referred to as a ‘malignant tumor.

Because of their more aggressive and invasive nature, malignant tumors are generally more serious than benign tumors. 

Here’s our guide on how to cope after your cat is diagnosed with cancer.

What Are the Common Signs and Symptoms of Cancer in Cats?

By nature, many cats will hide their issues and discomforts, which can make spotting any symptoms tricky.

So one of the best ways to stay on top of any early signs of illness or cancer is to attend your regular veterinarian checkups and increase the frequency of these as your cat ages. & perform gentle examinations at home once a month

Be sure to keep a note of any behavior changes regularly too!

Here are some common early signs that should warrant a visit to your vet, if you notice them in your kitty:

  • New, enlarged, or changing masses or bumps
  • Sores or cuts that don’t heal 
  • Abrupt or chronic weight loss or weight gain
  • Changes in appetite
  • A persistent cough or excess sneezing
  • Lameness or stiffness, or difficulty moving
  • An unpleasant odor from the mouth
  • Difficulty breathing, eating, or swallowing
  • Difficulty using their litter tray, constipation, diarrhea 
  • Bleeding or discharge from any area, especially the mouth
  • Lethargy and excessive tiredness
  • Excessively timid, or hiding more than usual 
  • Nosebleeds 
  • Seizures
gray cat laying in bed after high limp amputation
Yoda post-amputation from having FISS cancer

What Causes Cancer in Cats? And Can You Prevent Feline Cancer?

When receiving your kitty’s diagnosis, you might be hit with a wave of guilt. But understand that cancer is similar in cats as it is with humans — it’s often a random concoction of genetics, timing, and environment that can spark a sudden growth. 

If you are reading this post, know that you are already a wonderful owner, and your cat is lucky to have you by their side. This is something I had to overcome to help Yoda and be there for him in the way that he needed me to be. 

While there is no way to guarantee your pet will never get cancer, the latest cat cancer research has provided the following suggestions as to how to lower that risk.


Interestingly, some of the risk factors for cancer in cats are very similar to those in humans. Research shows that exposure to tobacco smoke, asbestos, prolonged sunlight, and lack of exercise has been linked to increased risks of cancer development in both cats and humans. 


It’s also been suggested that keeping your cat away from lawn chemicals, paints and solvents is wise. So if you’re having a garden or decoration overhaul, consider keeping your cat somewhere safe during this time!


Keeping cats indoors has been shown to prolong their life, with indoor cats having an average lifespan that’s almost three times that of outdoor cats. This also reduces their chances of catching the Feline Leukemia Virus. 


Some breeds are also prone to different types of cancers and are simply genetically much more likely to develop those diseases. So reading up on your breed can give you an idea of what to look out for. 


As we found with Yoda, vaccination and injections have been linked to developing Injection Site Sarcoma. You can read more about the possibilities for preventing sarcoma in our dedicated blog post. 


Diet is of course a hot topic when it comes to our kitties’ health. 

One study suggested that adding vegetables to your cat’s diet could reduce their risk of cancer, but this relied heavily on owner recalls. And it can be hard to remember what we had for breakfast let alone how many vegetables our cats had! 

To date, there aren’t any large-scale and robust studies linking cancer to diet. 


You might have read that carbohydrates can ‘feed’ cancer. 

According to the Animal Cancer Foundation: ‘At this time there is no evidence that a diet with a low, moderate, or high carbohydrate content has any bearing on cancer development in dogs and cats.’


Even though no studies have been able to effectively prove a clear link between obesity and cancer in cats, excess weight is a proven risk factor for other problems — joint disease, diabetes, skin disease & breathing difficulties. 

So maintaining a healthy weight in your kitty is important. 


There’s a heap of research around neutering and cancer, which can be all pretty contradictory. 

A recent review suggested that ‘the advantages of neutering seem to outweigh the possible increase in the risk of developing cancer.’But it’s best to discuss your individual kitty’s needs with your vet, as spaying a female cat when she is young can greatly reduce the chances of breast cancer occurring. 

Treatment for Cat Cancer

There are many types of treatment options for your cat that apply to both cancerous and non-cancerous tumors. 


For an isolated lump that has not spread, surgery may provide a quick cure, but it does depend on where the tumor is growing. Brain tumors, for example, are very difficult to remove in cats.  


Luckily, veterinary chemotherapy usually has few side effects, or none at all, because the doses used are so much smaller than those used in humans.

Unfortunately, it does not usually cure cancer, instead, it is used to slow the cancer and relieve symptoms. Usually carried after surgery if it has not been possible to remove the entire tumor or those cancers that are not presenting with a tumor.  

Possible side effects from chemotherapy include a reduced appetite, vomiting or diarrhea & reduced immunity. So your kitty will need extra special care during this phase of treatment. 


This treatment is only available at a few specialist centers, which might mean traveling long distances (which we found tough!) Again, it does not usually cure cancer, but can greatly reduce its aggression. Usually, your pet will need to be sedated for this. 

When choosing treatment options, your vet will take into account several factors — age, the chance of success, and the possible side effects. Ultimately, quality of life is hugely important, and if your kitty is in severe pain that is unlikely to improve, your vet is may encourage you to choose euthanasia. 

Of course, the choice is always yours in these situations, so take the time you need to make informed decisions about your cat’s diagnosis. 

Yoda post-amputation

Are There Natural Remedies for Feline Cancer?

Looking online you might come across anecdotes and stories of pets fighting cancer with natural remedies. And as long as the remedies don’t interfere with any of your vet’s treatment plans, it could be worth investigating these holistic approaches to cancer treatment. 

Although there’s no robust research in cats and dogs, there are some studies of herbal medicine’s effect on cancer with rats, mice, hamsters, and guinea pigs. 

Mainly, they show how herbs can be used to help manage the side effects of chemotherapy, improve overall wellbeing, and support areas that are affected by cancer.

For example:

Several other studies suggest similar effects from several herbs, mushrooms, and antioxidants. If you are interested in these, speak to a Veterinary Herbalist, or enquire with your vet for a referral to one. 

Feline Cancer Survival Rate

Can cats survive cancer? Yes, they can. While the odds aren’t necessarily in their favor, Yoda is proof that they can pull through — even if it means an ongoing strategy to keep cancer at bay.  

Dave Ruslander, a veterinary oncologist and past president of the Veterinary Cancer Society, says:

‘Survival rate for cats is probably less than 50%. But it all depends on the tumor type, when it is found, and how it is treated. Things are changing so fast, not just in terms of treatments but also clinical trials or novel treatments, that there may be treatments available that most veterinarians aren’t aware of. You may think there’s nothing that can be done, but things are changing all the time.’

The Wrap Up — Feline Cancer

We hope this article has given you the knowledge and insight to explore these options, and to find hope and steps ahead, even when the world seems dark after a diagnosis. 

Perhaps it’s helped you feel more prepared for if you ever find yourself standing in the vet’s office receiving this news. Or maybe it’s just helped you think more deeply about prevention, individual healthcare for kitties.

One thing we know is that even when the world seems dark and diagnosis looms, our cats are a special ray of light. 

Yoda has been a soldier and shown such strength through his treatment and subsequent amputation. It has made us appreciate him in a whole new light, and find such gratitude in the small joys he still finds in every day. 
If you want to share your cancer experience with us, please comment below or follow us on our Facebook, Instagram, and TikTok. We’ll keep you updated on Yoda’s progress and provide a space for comfort and conversation around feline cancer. You aren’t alone <3