Common Types of Feline Cancer and What To Do About Them

A cat can develop a variety of different types of cancers, just like human beings and other animals. And, just like a family member being diagnosed with this disease, having a cat diagnosed with cancer can cause you to feel overwhelmed, afraid, and worried about your beloved pet.

But, as terrible as a cancer diagnosis can be, it is not always a death sentence. For one thing, certain types of cancer are worse than others, and second, today’s chemotherapy treatments are producing more positive results than ever. Still, understanding what your cat could be up against will help you deal with her journey should she ever be diagnosed with cancer.

Here are the top five kinds of cancer in cats and the medicines used to treat them.

common cat cancers


Lymphoma is the most common type of cancer to affect felines. This type of cancer develops in a certain type of blood cell in the body called lymphocytes, which are found in the lymphoid tissues. Lymphoid tissue can be found throughout the body so this type of cancer can develop in a variety of different areas, such as the liver, the kidneys, the spleen, the GI tract, and elsewhere.

Lymphoma can develop in any age, sex, and breed of cat, but it is most commonly seen in cats aged between 2 to 6 years. Cats that already have the feline leukemia virus (FeLV) are much more at risk of developing lymphoma. Popular drugs for treating Lymphoma include cyclophosphamide, L-asparaginase, and lomustine.

Feline Leukemia Virus (FeLV)

Feline leukemia virus attacks a cat’s immune system, and while it is not necessarily a type of “cancer,” it is an illness that causes a variety of different types of cancers in FeLV-infected cats. The two most common cancers associated with FeLV are lymphoma and fibrosarcoma.

This infectious disease is most typically found in male cats aged between one to six years, but any sex, age, or breed can contract it. Because this disease is transmitted via blood and saliva, outdoor cats are especially prone to getting it.

Feline leukemia virus is treated with a synthetic analog of the drug thyamidine called zidovudine, or AZT. This medication was originally designed as an anti-cancer agent but it was ultimately discovered to be more effective against the progression of FeLV.

Mammary Cancer

Approximately 85% of all mammary tumors in cats are malignant, and these types of tumors metastasize very quickly, making early detection important. Mammary cancer is most commonly found in female cats, but while rare, it is not beyond the realm of possibility for males to develop it as well. Older cats are the most at-risk for mammary cancer, but the risk is reduced in cats that were spayed prior to their first heat.

Surgical removal of the tumor is the usual treatment for mammary cancer, followed by a chemotherapy program consisting of doxorubicin and cyclophosphamide (or carboplatin).

Squamous Cell Carcinoma (Skin Cancer)

The majority of skin tumors found on cats are squamous cell carcinoma, or skin cancer.  Such tumors tend to be light-colored or unpigmented and they are most commonly found on the ears, the nose, and the eyelids because these areas are the most exposed to the sun’s rays (overexposure is a leading cause).

Any sex, age, or breed of cat can be susceptible to skin cancer, but it is most commonly found in hairless breeds or light-haired cats. Popular chemotherapy drugs used by veterinarians to treat squamous cell carcinoma include cyclophosphamide and mitoxantrone.


Fibrosarcoma is an aggressive soft-tissue cancer that is not uncommon in cats, but as aggressive as the cancer is, it is usually slow to metastasize. Fibrosarcoma starts in the cells found in the body’s connective tissues as well as in subcutaneous connective tissues. Chemotherapy treatment is required after the tumors are surgically removed in most cases because fibrosarcoma can grow back.

The chemotherapy drugs most commonly used to treat cats with fibrosarcoma include carboplatin, cyclophosphamide, doxorubicin, and vincristine.

What You Can Do About a Cat That’s Been Diagnosed With Cancer

If your cat has been diagnosed with cancer, then you can request your vet to purchase her chemotherapy medications from Diamondback Drugs. We’ll provide you with a free quote for the medications so you know how much they will cost before the scripts are filled. Try us today. Diamondback Drugs can help save you money on all of your cat’s chemotherapy medications.

Author: Giano Panzarella