Cancer In Cats: What You Should Know

Your cat isn’t just a furry, friendly roommate, your cat is a beloved member of your family. When a cat is diagnosed with cancer, it can be devastating. Did you know that more than 6 million cats are diagnosed with cancer every year? Cancers, like lymphoma, are even more prevalent in cats between the ages of two and six. Cats that have feline leukemia virus (FeLV) are also at significantly higher risks of developing cancer.5Thyroid Cancer in Dogs and Cats

Would you know if your cat was suffering from cancer? Many pet owners don’t, and we want to help.

Feline Tumor Risk Factors

Unlike in dogs, cats are not as divided by breed. This makes it more difficult to determine if certain kinds of cats are more prone to cancer than another. In fact, risk factors for cancer in cats are very similar to those in humans. Exposure to tobacco smoke, asbestos, prolonged sunlight, and lack of exercise have often been linked to increased risks of cancer development.3

Keeping your cat indoors can keep your cat healthy and prolong their life. Indoor cats have an average lifespan almost three times that of outdoor cats.7

Cat Cancer Varieties

  • In cats, one especially dangerous kind of cancer is an injection-site sarcoma – (ISS). Injection-site sarcomas are malignant cancers triggered by injections of material placed under the skin, causing chronic inflammation. Any injection can result in the formation of an ISS, including long-acting steroids, antibiotics, insulin, and even subcutaneous fluids such as saline. This kind of cancer is especially damaging and rapidly progressing. Be sure to keep an eye on your pet after any injections.2
  • Mammary cancer is among the most common form of cancer in cats, but fortunately, this variety is one that can be prevented by spaying. Cats spayed before six months of age are seven times less likely to develop mammary tumors than cats spayed after six months of age.4
  • Feline leukemia virus (FeLV)is one of the most common infectious diseases in cats, affecting between two and three percent of all cats in the U.S. Infection rates are significantly higher (up to thirty percent) in cats that are ill or otherwise at high risk. This virus is the most common cause of cancer in cats.6
  • Bone cancer (chondrosarcoma) can impact the limbs, spine, skull, pelvis, and skeleton. These tumors can be primary tumors (within the bone) or secondary tumors (spread to an adjacent site) like multiple myeloma of the bone marrow or metastasize from a distant site, such as transitional cell carcinoma. Primary bone tumors are uncommon in cats. Osteosarcoma is also the most common bone tumor in cats, but the behavior of this tumor type is less aggressive than in dogs.8
  • Brain tumor (meningioma) is more common in male cats than female cats. Meningiomas are primary brain tumors and account for 56-69 percent of all brain tumor types in cats. They are typically slow-growing tumors in cats. Other primary brain tumors include lymphosarcoma (LSA), pituitary tumors, gliomas, ependymoma, choroid plexus papilloma, medulloblastoma, olfactory neuroblastoma, and gangliocytoma.9

Cat Cancer Symptoms

As a pet owner, you should always be observant of any changes in your pet’s physical appearance and behavior. Not all cancer warning signs are apparent right away, with some changes developing over time.

If you notice any of these symptoms of cancer in your cat, contact your veterinarian to check things out as soon as possible. Depending on the cancer type and stage, your pet’s health can deteriorate very quickly, so it’s always best to get an exam. When in doubt, get it checked out.

  • Enlarged or changing lumps and bumps
  • Sores that do not heal
  • Chronic weight loss or weight gain
  • Change in appetite
  • A persistent cough
  • Persistent lameness or stiffness
  • Unpleasant odor from the mouth
  • Difficulty breathing, eating or swallowing
  • Difficulty urinating or defecating
  • Bleeding or discharge from any opening

Regular wellness exams will provide your veterinarian the opportunity to check for signs of cancer, but you can take a more proactive approach to your pet’s health by looking for these warning signs regularly.3

Just like for our own health, wellness exams can help catch any potential problems early – sometimes with lifesaving results. The same kind of lump and bump check can be a life-saving routine for our cats too.2

What to Do If Your Cat Has Cancer

Oncology for cats is available! If your pet has been diagnosed with cancer, contact our Pet Advocates at (833) PET-HERO or your local PetCure Oncology center. Our veterinary cancer experts are ready to help answer your questions.


RELATED: Tips For Caring For A Cat With Cancer

ALSO: Did you know that PetCure Oncology treats cats with feline idiopathic cystitis? Using low-dose radiation, many cats can get relief from this chronic condition.


1. National Cancer Institute Center for Cancer Research. Accessed July 25, 2018
2. Morris Animal Foundation. Accessed July 25, 2018
3. Morris Animal Foundation. Accessed July 25, 2018, from https://www.morrisanimalfoundation.org/sites/default/files/files/2018-03/00000-MBS_UTF_CancerChecklist_F1.pdf
4. Accessed July 25, 2018, from https://www.petmd.com/blogs/thedailyvet/drjintile/2014/december/finding-causes-cancer-cats-and-dogs-32278
5. Diamondback Drugs. Accessed July 25, 2018
6. Cornell University College of Veterinary Medicine. Accessed July 25, 2018, from https://www2.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-leukemia-virus
7. Pet Health Network. Accessed July 25, 2018, from https://www.pethealthnetwork.com/cat-health/cat-diseases-conditions-a-z/cancer-and-cats-what-every-pet-parent-should-know
8. American College of Veterinary Surgeons. Accessed August 8, 2018, from https://www.acvs.org/small-animal/bone-tumors
9. Veterinary Society of Surgical Oncology. Accessed August 8, 2018, from https://www.vsso.org/index.php/education-new/cancer-information-new/cancer-in-cats-by-tumor-type-new/9-education-1/education/309-brain-tumors-feline

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