The 3 Most Common Types Of Cancer In Cats

Written by: Adri Sandoval
Adri Sandoval is the Special Projects Manager for iHeartDogs and iHeartCats. Her work has deepened her love for animals, fostering a strong passion for rescue and animal advocacy.Read more
| Published on May 25, 2017

We love our cats to the fullest, and sometimes we force ourselves to forget that they have a much shorter lifespan than we do. We may refuse to acknowledge that our cats can develop health problems as severe as cancer. Cancer is less common in cats than dogs, but about 1 in 5 kitties will develop cancer in their lifetime, and early detection is key in any treatment plan.

Here are the 3 most common types of cancer in cats.

#1 – Lymphoma

The most common cancer found in cats is lymphoma, which is a type of blood cancer caused by proliferation of the white blood cells that protect the body from infection. Lymphoma typically affects the intestines, nasal cavity, lymph nodes, kidneys, or liver.

Prior to development of a vaccine, feline leukemia virus (FeLV) was one of the leading causes of lymphoma in cats. Even if your cat is never around others, the FeLV vaccine is a good idea since it can help prevent lymphoma.

Chemotherapy may be expensive, but it can be very effective in dealing with lymphoma. Many cats will go into remission, some for 2 years or longer.

#2 – Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) is a type of skin cancer that usually develops on exposed skin such as the ears, nose, and eyelids. It’s most prevalent in white cats in sunny climates. Keeping your cat indoors will help prevent this form of SCC. SCC can also develop in the mouth. Researchers are investigating new treatments, but oral tumors have a poor prognosis with current treatments.

#3 – Fibrosarcoma

Fibrosarcoma is an aggressive form of cancer that attacks connective tissue. It often develops at the site of injections for vaccines, insulin, subcutaneous fluids, or other necessary injections. This form of fibrosarcoma is called feline injection-site sarcoma (FISS).

FISS is a fairly rare side effect of vaccinations, only occurring in 1 cat per 10,000 to 30,000 vaccinations, according to the American Veterinary Medical Association. This isn’t a good reason to skip vaccinations, though vets may limit the frequency and location.

Treatment for any form of fibrosarcoma is surgery with or without radiation or chemotherapy.


Cats tend to hide their symptoms, so it can be difficult to catch cancer in early stages, especially when there aren’t any noticeable lumps or bumps. Vomiting and diarrhea can be signs of gastrointestinal lymphoma. Some cancers may cause fluid in the lungs, which can cause difficulty breathing. If your cat is acting lethargic or just not themselves, it’s always better to go to the vet sooner rather than later, since even relatively treatable cancers rely on early detection.

(H/T: Pet Health Network, WebMD)